This same e-mail was posted here a couple of weeks ago and is largely incorrect. Our moderator, Pat, provided quite a bit of information on this internet hoax. One example that I am aware of (because I ride a BMW motorcycle) can be seen at: http://www.americanmotor.com/news.cfm?NEWSID=1778 . This website details BMW's contributions: BMW donated 100 police motorcycles, 10 X5 Sports Activity Vehicles, and $1 million in cash, a total contribution of $2.4 million to New York City and those affected by the attack. As Pat pointed out, several other of these claims are likewise bogus. Unfortunately, once these things make their way into the Web, they take on a life of their own.
You can find further information on this anonymous e-mail at the Urban Legends Reference Pages at http://www.snopes2.com/rumors/cars.htm and a more detailed look at these erroneous claims at http://www.womanmotorist.com/ftrs/bs-911-automakers-2001-01.shtml .
Undoubtedly there are many foreign companies doing business in the U.S. that didn't contribute; however, the same can be said of many U.S. companies. But, back to the point at hand, the e-mail you received is a work of fiction.