and no amount of spurious claims will make our trade with EU disappear either. however the point being made is that the consequence of negative impact to trade occurs to both sides. you may want to focus on the % of the total because that suits your argument, but if no sensible trade deal leads to say 10% reduction in car sales to UK, thats going to have a tangible impact on GDP of major countries in EU. (the reverse is true, but less % because of the net flow to EU)
Every negotiation has someone with the stronger hand. The sooner people realise we are not in box seat the better!
People here seem to think that with our 40 reliant on EU this makes us strong.