you could always do what I do and refer to lexus' as chromed up, overpriced Toyotas (and Acuras chromed-up, over priced Hondas). That always ticks them off. the old, "I wouldn't pay an extra 5 grand for a name" argument. ( It really works on Audi A4 owners who really drive a Jetta with 4 rings on the grille instead of one)
And as for the Prius thing, you could quote the study done about 6 years ago that found(with spotty research and a few far reaches streatches of for full disclosure), for the same environmental damage of building a Prius and shipping it to the US, you could build and drive a Hummer H2 for 5 years.... that REALLY upsets the tree huggers!