I'll have a crack at it.
/k/ - Lotus E22, because le maldozer
/pol/ - Auto Union grand prix car, because several influential Mercedes were designed by Jews
/leftypol/ - Estonia 18, because it's a communist car that is crap
/b/ - Life L190, because it's a freakshow of low effort terrible design
/cow/ - Andrea Moda S921, because it's not actually a terrible car, but the team was run comically by a lolcow