I'm in the same boat as you actually. No real job, car is temporarily out of commission, my girlfriend is getting tired of waiting for me to get a job, no family support, etc. It's really hard to be positive when everything around you seems to be holding you back. In all honesty, it's getting hard to wake up every morning and try to make something of the day.
What gets me through it though, are the people you surround you with. I've made made friends over the past couple of months who are interested in things like cars, football, stuff of that nature and it's been a huge help. Being able to get away from things, laugh about stupid shit that's said/done, has helped a lot.
Job hunting is hard, but it helps you feel like you've done something, even if you know you won't hear back from anyone. And when I get tired of that, I go work out, read a magazine, watch a movie, or go for a drive like you do. As gay as it sounds, MafiaWars on Facebook has been a good time waster too. But at this point, I'll take what I can get.
A lot of good advice in here. Definitely given me some ideas to help me personally.