They do it for effect. Would anyone care if a Lexus got crushed or run off a cliff. Most people would probably be happy to see that. Do the same thing to a Mercedes and the audience is agasp. Forget about the bad guy that deserved to die inside it, a Mercedes was wrecked and that is the emotion they are trying to elicit from the moviegoers. What good is a movie if it doesn't make you feel anything? Then all movies would be the Fast and the Furious? Can you image if you had watched that movie and they were crashing 300SLs or Mclaren SLRs instead of civics? I agree it would have been a heartwrenching shame and in the case of crashing a 300SL I think it should also be a capital offense, but it would get people pretty emotional.

__________________
Jason Priest
1999 E430
1995 E420 - retired
1986 420SEL - retired