I ALWAYS ask the owner to let me start the car cold.
I tell him not to start the car that day. You want to hear the motor warm up. Hard starting?
Run it in 1st gear up to 3500 rpms and let it decel back down still in gear a few times. See if it pops out of gear or not.
Look for for violent oil leaks. Any funky tire wear or pulling from side to side brakes on and off.
Sniff for burning oil or clutch/brake whiff.
Any rouge mods? 914 butchery is to be avoided!
If it has a six, tell me! <_<