It's your car, you call the shots. Instead of having to tag along with somebody, else, make deals, whatever.
Of course...if you have a car, don't be a dick.
One of my roommate's with no car almost missed out on a piece of ass b/c of it. I was working off a real sonuvabitch of a hangover but I felt bad enough about his whining so I gave him a ride. Which leads to a funny story:
The next morning he calls me while I'm on watch to tell me she(Pcola skank) can't drive on base, so she had to drop him off at the gate. He also left his ID in the room, so he needed someone with an ID to get him in anyway. To avoid being seen by a staff member driving in(since the ice cream suits make us high vis targets) he's freaking hiding in the bushes by the gate while he's calling me.
I had to wake some people up to go out and get him, or he would've been in for a REAL bad day.