Here is the clip:
BBC Top Gear Insults Mexicans and their Culture Video - Videos - MetaTube
Yeah, it is a little harsh, but doesn't seem all that different than when James May said that "France is a country you have to drive through to get to Italy, that is all it's for", and the French were "a bunch of treacherous, lamb-burning, work-shy peasants".
Suck it up Mexico.