If we have no political reason to be in the EU then the only logical conclusion to take from that, is to leave. We would have far greater economic freedoms outside it.
There was never an economic reason to enter the EEC, as it was then, it was always political, despite what the politicians and media argued at the time. The proof of that argument is the we didn't join the Euro and have benefited because of that decision.
We already had EFTA and the Commonwealth. We gave up economic advantage to join the EEC and the proof of that argument is the collapse of our industry. We were geared up as a world trade country not just European, all of our production had that market in mind. Our cars were unsuitable for Europe our manufactured goods similar. We worked in the imperial system, even though we had invented the metric system, because it suited our world trade. To change all of this (as we did) is one of the major reasons for our industrial collapse. While we were converting our country, other EU countries (Germany in particular) were busy exploiting our exposed markets. The politicians have served the UK very badly indeed and this has never been fully exposed because of our biased and controlled media who failed to ask the questions and concentrate on irrelevant nonsense to suit what they perceive as their personal interests.
As an engineer I assure you that the metric system is far easier to work with. 1 litre of water having a mass of 1 kg and 1 cubic metre of water having a mass of 1 tonne makes calculations very easy. And give me a litre of beer over a pint any day.
I don't think you can blame the EEC or EU whatever you want to call them for the collapse of our industry, try senior management, i.e. Michael Edwards at British Leyland and the unions with their left wing leaders, i.e. Arthur Scargill and the other twat at Ford, Derrick Somebody.
What chance did the british car industry have when rather than put money into R&D we lost money hand over fist fighting the Unions and paying top management ridiculous sums of money. The germans meanwhile were designing better cars. Car workers were paid bonuses based on profit so it was in their interest to work with management not against. All german car firms had, and I understand still have, union representation on their boards of directors.
You are right, our cars not being suitable for the European market, or any other market for that matter. Our answer to the early BMW 3 series???? The bloody Austin All-aggro or whatever they called it. You had to be a keen gardener to own one of those, it stored abouut 10 gallons of rain water in the boot!!!
Thatcher had to take on the Unions to save this country, like bad tasting medicine to cure an illness, Thatcher leading the country didn't taste very good at all. But cure it she did.
When it comes down to it the Germans employed team work, we used confontation. I'd rather work as a team. To blame the EU for the demise in british industry is akin to blaming immigrants for not having a job.