Ugh...
This has been explained again and again and again and again....
Imagine you see someone walking down the street smoking weed. You say to yourself "Hey, I thought that was illegal, but there's a guy doing it, right there, out in the open!"
What does this one instance of someone violating a rule mean to the overall legality of marijuana?
Nothing. Just because there are people who own infringing names doesn't mean that those names aren't infringing (blatantly so, in this case). It just means that they are getting away with it.
This domain is precisely the sort of name that total newbies register, because they don't understand that a lot of the brand names they speak of on a daily basis constitute a form of intellectual property and you cannot just go register domain names that infringe on the rights of trademark owners. They don't understand that you run a risk by registering names that incorporate trademarked brands and to justify their actions when called down about them, they point to other people 'who are doing it too.'
So, new guy, take this as a lesson. You really should not register names like this. Yes, you might get away with it, but somewhere at Markmonitor, an alarm is going off and the people who are in charge of keeping track of the Chevrolet brand know of you this names existence.