[Noah930]

I don't know if the questions you'd ask a turbo seller are significantly different than what you'd ask of a normally-aspirated seller. One thing I paid attention to, though, was how the seller drove the car on the test-drive. I had him drive the car, first. That way I could see if he was the kind of guy to let the motor properly warm up before getting on the throttle hard (and invoking the turbo), and if he was aware that the motor should cool gently for a few minutes before shutting it off, afterwards.

Otherwise, same questions of miles/track use/originality/maintenance/accidents/mods/oil consumption/rebuilds/etc apply.