At best, the factory exudes industrial romanticism. Robots weld together sheets of metal, and a new vehicle rolls off the assembly line every 68 seconds. For many Brits, though, the significance of these factory halls goes far beyond the compact cars produced here – it's about a brand that is intrinsically linked to their national identity. Around 15,000 visitors a year flock to Cowley, an industrial district on the outskirts of Oxford, the self-proclaimed "heart of the Mini".
They aren't just motorists either – they're fans, people like the elegant English woman who stepped onto the shop floor in mid-May. She was over 90 years old, could still drive and was a Mini enthusiast. She had recently purchased a Mini, the sporty John Cooper Works model, and now she had come to visit the car's birthplace, with her fingernails painted red, silver and black to match the colours of her new vehicle. For one particularly brand-loyal visitor, guest attendants at the plant even decorated a car with flowers and ribbons. He wanted to propose to his girlfriend inside.
First produced in 1959, the Mini has developed a certain aura over the years. The Beatles, Mr Bean and allegedly even the Queen have driven one. It is a British icon that survived decades of mismanagement by former owners. Not even the takeover by a German company could diminish its popularity – on the contrary. BMW invested more than €2bn in the Oxford plant, the oldest existing car factory in Europe, and the British supplier plants in Hams Hall and Swindon.
In 2001, engineers created a completely revamped Mini model, designed to appeal to a young and affluent demographic. BMW originally planned to sell 50,000 of them a year, but sales are now more than six times that.
It looked like a successful joint German-British venture. But now, the possibility of Brexit is threatening the most important criterion for the Mini's continued success: the cross-border exchange of goods and people.
Before the launch of each new Mini model, hundreds of specialised engineers commute between Oxford and production sites in Germany, such as Munich and Dingolfing. Not only that, most of the components come from non-British suppliers, with roughly 60% of every Mini being assembled using parts made abroad. Any delay could upset the finely tuned production plan.
As such, on June 23, the day of the referendum, voters will also be deciding on the future of the Mini.
The vote presents BMW with some awkward questions: to what extent should a German company meddle in British politics? And how should it respond if the British actually do decide to leave? Should it continue to invest as if nothing has happened, or should it turn its attention to other production sites?
Any ill-considered statement could stir up the mood even further and give more ammunition to EU opponents. So it was a very carefully worded email that BMW sent to the company's UK workforce in February.
The firm wrote that it was entirely up to voters to decide whether the UK should stay or leave, but BMW had "a view on the topic". After this introduction, the company warned of the risks of Brexit, noting that trade barriers would "mean higher costs and higher prices". The firm went on to say that one could not assume the UK would enjoy the same advantages outside the EU as it did inside.
Despite all precautions, the letter rubbed many people the wrong way. Conservative politicians accused the carmaker of "disgraceful scaremongering". Brexit supporters, who see the EU as a lobbying network for big corporations, criticised what they saw as an attempt to impinge on the rights of British citizens to cast their ballots freely.
The workers in Oxford have a more nuanced take on the issue. Many have a critical view of the EU, but have a low opinion of the isolationist rhetoric of the Brexiteers. The Mini plant provides a workplace for people from 66 different countries and the workforce is accustomed to exchanging personnel and expertise across borders.
Indeed, without skilled labour, money and ideas from abroad, the Mini would probably no longer exist today at all.
When Chris Bond started working in the production hall 42 years ago, the UK had just become a member of the European Community, the forerunner of the EU. Even today he remains sceptical of institutions in Brussels, which seem too bureaucratic to him. "But how do you want to change something," he asks, "if you don't belong to it any more?"
Bond is a union leader who is used to fighting for a cause. He remembers when the British automotive industry was embroiled in endless battles between workers and factory bosses.
The owner at the time, British Leyland, invested little in new plants and equipment and consequently the physical labour was gruelling. Bond hauled stacks of fenders and bonnets through the halls, which explains his stocky build today.
To fight for better conditions, more rights and higher wages, he and his fellow workers downed tools several times, bringing production to a standstill. They went on strike for a number of days each week, sometimes for over a year.
Today Bond, 63, has mellowed. "Back then we could only dream of the working conditions we have today," says the trade unionist, who sees the shrinking of the workforce from 28,000 to 4,500 in the wake of automation as a necessary evil.
The plant changed owners a number of times, and British Leyland became the Rover Group, but the Mini itself, including its antiquated production equipment, always remained virtually the same. In a bid to stay competitive, the owners kept the price of the Mini artificially low, and as a result the Mini posted only losses into the 1990s.
When BMW acquired the Rover Group in 1994, the workforce initially reacted with caution. Their jobs appeared to be safe, for the time being, but no one knew how long the Germans would hang on, especially as the company had a number of unpleasant surprises at the outset.
A legendary example was a personal appearance at the plant by then BMW CEO Bernd Pischetsrieder, who had orchestrated the Rover purchase. The workers proudly presented their paint shop, which they considered quite modern, and told him the facility was only 16 years old. Pischetsrieder merely shook his head before answering: "Why don't you build a new one?"
Today, the Mini plant has a paint shop that has become a model for the entire group. The painting process pioneered in Oxford saves space, time and energy and is now used in BMW plants around the world. As far as the British autoworkers are concerned, this is proof that both sides have benefited from the cooperation.
BMW learned other things from the British too. In 2012, the Germans came up with the idea of shortening the traditional tea break for the workforce, citing "hidden costs". A looming revolution was averted when Bond's union, Unite, threatened to go on strike, and BMW quickly abandoned its attack on British civilisation.
"Everyone here thinks the management under BMW is better," says Bond. Workers at the Oxford plant no longer have to perform tasks involving overhead work, and car bodies are rotated by robots so mechanics don't have to contort themselves any more as they work.
Bond is on first name terms with the plant's current managing director, Frank Bachmann, and most conflicts are resolved at informal meetings. Recently the union activist managed to wrest a 10% wage increase from the company, entirely without strikes or production stops, after Bond pointed to the high sales of the new Mini Clubman.
The Mini, in short, has been a German-British success story. But Ian Robertson, the company's sales and marketing chief, fears for the partnership's future.
Robertson, who sits on the 22nd floor of BMW headquarters in Munich, can see problems on the horizon even as he looks out of his office window. The sun casts an early summer light over the city's Olympic Stadium across the way, the Frauenkirche cathedral in the city centre and the Alps to the south. Robertson complains about the wind turbines on the horizon, which offend his sense of aesthetics.
Ever since the threat of Brexit first arose, Robertson, who hails from the UK, has been sounding the alarm. "We're moving components, engines and cars right across Europe," he says, "and we need to be able to plan that with certainty."
As well as the Mini, BMW also produces Rolls-Royce sedans in the UK. The company aims to cover all segments of the premium market, from compact cars to luxury town cars, and these two British brands are at the very core of BMW's plans.
But sometimes cultures clash, even when one Briton meets another.
In early January, Robertson gave the British prime minister, David Cameron, a tour of the manufacturing halls in Munich. The executive casually commented that BMW, together with its dealer network, employs 24,000 workers in the UK, adding that remaining in the EU, under these circumstances, is "advantageous for the United Kingdom".
It was a sober analysis by the English BMW executive, yet the British media seized on his comments as a thinly veiled threat.
In reality Robertson is keeping all options open, though he is unwilling to speak about possible reactions to Brexit. "We have no plan B right now," he insists.
BMW surely wouldn't close the plant in Oxford, because the firm has invested too much in it. But if Brexit were to reduce the location's attractiveness, BMW might redistribute its resources – to a partner plant in the Netherlands that is already producing Minis, for instance.
Either way, Cameron cannot afford to antagonise companies like BMW. In his first term in office, he promised to help the domestic auto industry make a comeback, but the most famous British brands had by then already fallen into foreign hands, so that would mean supporting non-UK companies.
At the old Rover plant in Longbridge, where Minis used to be produced, Chinese owner SAIC is now manufacturing cars under the MG brand name. Jaguar and Land Rover belong to India's Tata Group, and Bentley has gone to Volkswagen. Rover, later sold again by BMW, has disappeared from the market altogether.
According to a study by the auditing firm KPMG, remaining in the EU is "vital" to the "long-term prosperity" of the entire British automotive industry. The sector needs the EU not only as its most important sales market, but also as a negotiating power, for example, when new free trade agreements are on the table.
Up till now, Brexit has remained a theoretical scenario. But what if it actually happens?
Andrew Smith has grappled with this question. The Oxford MP's constituency office is tucked away in a terraced house in the industrial district, only a few hundred metres from the Mini plant.
The cramped room is brimming with stacks of pro-EU posters and flyers. "Britain is better off in Europe," one of them reads. Smith, the Labour Party representative for Oxford East, sits among the paperwork drinking coffee from a trade union cup.
When BMW decided to try the new Mini in Oxford, Smith was chief secretary to the treasury under Tony Blair. He jumped into his car, drove to the plant grounds, sounded his horn and raised his arms in the air. The workers in front of the gates cheered as if England had just won the World Cup. It has been easy ever since for Smith to campaign in favour of the EU. All he has to do is point to the Mini, a model project. The economy in the region is flourishing and unemployment is almost non-existent. Smith warns of the possible economic repercussions of Brexit, but he doesn't believe in horror scenarios. "Even if Britain voted to leave the EU we want to stay in the single market," he says.
If the voters decide to leave the EU, Smith has a contingency plan. He would immediately contact the BMW board of directors with an urgent request: please keep the Oxford plant open.
The workers are also counting on the Mini's success to continue. The new Clubman has only just been introduced to the market and preparations are already underway for the next generation of Minis. Recently, a 12-member project team began developing a concept for the future, and they hope to produce the new models in Oxford.