I would say do the tires and maintenance and drive it another year or so but watch gas prices and if it looks like they are going to jump up get rid of it asap.
Unless there is some real good reason (not because you want something different or because you do not want to spend for maintenance) you should stick with any car you have until you owe less than it is worth. And better if you keep it until it is paid for. And best yet if you drive it until it becomes an antique and gians value.
No, no, no. Like someone else said, hold on to your jeep unless you are in a bad need to sell it. By the way, you will maybe get $5,000 for it, as you can buy a 2008 Jeep Grand Cherokee for $15,000 right now in this economy. Don't do it!!!! If you must, wait til next year when you owe less than the car is worth.