I need a new car

I currently drive a '99 RAV4 that has served me very well. But it's 8 years old and I'm ready for something new. If someone else would like to cover the car payment that would be very nice because I hate having a car payment and if I get a new car we'll have 2 car payment in the family. However, this morning the car wouldn't start. I tried everything I could think of (I was fairly sure it wasn't the battery) and finally had to call AAA. The guy checked the battery (with a very cool portable diagnostic computer) and it told him to just start the car. He was able to get the car started eventually and gunned it for about 5 minutes. Then he told me to leave it running for another 10 before I went anywhere. He thought maybe there were deposits in my valves. Now I have to go do some research to see if he was right or talking out his ass.