New Car or More Money

I have a 1997 Pontaic Grand Am GT, I have had it for alomost four years, it's now pushing 160,000 miles, and it has been a very good car, but I have put alot of money into it. I have had to redue my cyclinders, which cost me over $2,000, that was only 1 1/2 years ago and just the other day I was on my way home form school and my tentioning thing (that holds my belt on) broke into pieces. My battery light came on, which I had no idea what it was for, I called my machanic(I have him on spped dial)to see what was going on. He said that it was probably my alternater but thank god it wasn't, that would have cost me close to $400. This I think will cost about $200, by the time I get labor in. I have had so many problems with my car, but I just keep fixing them. I think that I have drove my loaner car just about as much as my car. Just before school started I got my tires rotated, and they didn't tighten my lug nuts all the way, so on my way home from Lacrosse my car started to shake really bad, I thought maybe I had a flat tire, but I didn't. Again I called my machanic and he told me to bring it up right away. By the time I get to Waukon my lug nuts are 1 turn away from being off!!! On both of my front tires!! My daughter and I could have been in a bad car accident! I called the people who rotated my tires and they tell me that I need to check my lug nuts every so many miles, and that it was on my invoice. Of course, I don't have that anymore, but I will never go back to Goodyear Tire in Waukon. As a result of that I had to put on new bolt things (that hold your tire on) because mine got stripped out. They wouldn't even pay for part of the repair. So now that it is getting to be winter time, and I drive from Lansing to Lacrosse, everyday, I have been thinking about getting a four-wheel drive vehicle, but am unsure what to get? Anyone got any suggestions, I need a good gas mileage, 4 wheel drive vehicle that doesn't cost me a arm and leg, because as we all know, college students don't have a lot of money.