If you had any real grasp of the car industry you'd understand that diesel is the single biggest issue affecting the UK car market.
Look at Jaguar/Landrover most of the models they sell are diesel and they are now only just catching up by introducing hybrid models. They are also losing out due to a massive drop in sales in Asia, is that caused by Brexit?
My ignorance forces me to listen to everyone. I give more weight to people who do have a "grasp" rather than (sometimes unaccountable) politicians trying to climb the greasy pole.
Motor manufacturers have overwhelmingly been in favour of
just in time and an ability to plan and invest. They have been against delays in reaching a deal (which Brexitists once told us would be easy) and against threats of "no deal".
So diesel, yes, a big factor, especially in the UK but global market conditions and tarrif wars, the switch to electric vehicles, smart cars and silicon valley v motor manufacturers and the need for multinational alliances and therefore governance, eg How might a possible Peugeot : Fiat-Chrysler merger impact upon Nissan?
But also, Brexit and no deal too, if you choose to listen to the trade rather than the Politicians. If you have any specifics about how a "no deal" might help motor manufacturing, I'll certainly listen.
What bemuses me is the immaturity of threats to damage German car sales in the UK via a "no deal". The mutual destruction argument. It's the language of the jihadi. I just don't get how that kind of threat might impress anyone outside a believers' bubble?