The only way you can possibly get into mainstream automotive manufacturing is if you have a genuine USP
Clive Sinclair did with the C5, but it was still never going to sell.
Tesla are held up as the gold standard of electric cars, but if you sit in one and a Merc of the same value they don’t half seem crap in comparison.
And if you say all the value is under the skin, take a look underneath one. The standard of welding, for instance, would not pass muster on the cheapest bike in Halfords.
It’s all marketing; distract the punter with the flappy doors and the big tv, and don’t let them spot how badly the bootlid fits.