Your analogy works in this way: they both require artists/craftsmen of the highest caliber, the work produced is the pinnacle of their class.
However, it falls apart because one requires far more skill; an engineering background is paramount for the development of high quality automobiles. If you give any idiot the raw materials required for haute couture it is still possible for him to produce clothing (technically not haute couture). Obviously this is not the case with automobiles. Also, let us not forget how truly great an engineering feat Bugatti automobiles are, first and foremost they are race cars.
Also, I hate superfluous light that some here view haute couture in... But I digress.