My mother has a similar age Avalon. Kind of a dorky car, but I have borrowed it several times, and it has gotten me great mileage, especially considering its size and comfort. Its a bit old now, but I got her a new kicking stereo system, and its still running well..
The factory stereo in mine sounds even better since I hooked up a MP3 player DIRECTLY into the back of the CD head unit with an adapter from Crutchfield. Can definitely tell a difference in clarity and stereo imaging vs. playing CDs.