Tranny slippage, burnt fluid, dirty fluid, and leaks.
Motor oil clean and in range. Oil leaks. No funny noises. check the motor mounts by dropping into gear, (hood up) press brake firmly, and rev the motor. Look for the motor to lurch. (bad)
Bring some tools and check the differential oil. Mine looked like milk chocolate I discovered when I got home.
If it's a 5 speed check that oil too. Also look to see if the tail shaft is covered in oil. Check for slop in the shifter.
Watch for any crazy wiring. Look under the hood and under the driver's dash especially.
Tire wear to diag alignment.
Check all windows and locks, power or manual.
Check the cruise control.
But really for $900 expect to have a fixer-upper. But that gives you haggle room. Bring cash in $50s or $20. It looks like more than 9 one hundred dollar bills. I've saved thousands over the years with this tactic. They see all that money and want it.
