look for good compression & leak down results
general poor condition , paint fading , flaking , excessive wear on seat , wheel , gear shift , door trims . or replaced items indicates high km
rust , undercaridge and wheel arches especially
accident damage , especially if not a sevs imported car , undercarige again look for new welds/seems in engine bay also
not as bad but a pain would be turbos health , eletrical issues and 4wd/4ws problems . but definetly rust , accident damage and engine health are you main concerns .
a 17000$ gtr would probably have all of those , save up and get a mint 94 for 30k and then you will get a very nice car