Buying A New Car?

Have you ever had to buy a new car? I'm dealing with this struggle right now.

I currently drive an 03 Chevy Tracker- perfect for winter conditions and hauling a lot of stuff. But I recently found out I could buy an 08 Pontiac G6 - not so great for snow and not a lot of room but way better gas mileage. And with gas prices the way they are, that's not all bad. I want both cars, but that can't realistically happen, so I have to pick one.

What do you guys think? Do you have any tips for me while I make this decision?