If you're finicky, try the emergency brake. Give the steering wheel a twist if possible, then get under the car and visually check the steering linkage. Take a look at the tailpipe. The cleaner it is, the better. Check the tires.
Uneven wear is bad.
If it has disc brakes, check for wear or grooving. Give the car a bounce. Check the registration sticker. In California, you're obligated to pay any back registration fees the last owner didn't pay before you can register the car yourself. Stick around until the end and watch the competition.