whats the mileage?
have there been any previous engine or body work done?
were there any electrical damage or electrical problems?
if there were problems with the car, was it taken care of right away and what caused it?
was the car covered under warranty by a toyota dealer and was serviced, or was it taken care of by another local shop?
what aftermarket parts are on the vehicle?
does the a/c work good?cold?
do they have any maintenance proof?
how often was the oil changed? what intervals? 3k miles?
how often was the coolant flushed and re-filled?
was the car in ever involved in an accident?
how many miles are on the tires? do they still have a lot of tread life?
what was their driving style? fast? racer? granny driver?
etc etc etc and make sure you do a good inspection on the car. good luck