Well, the 3.2 can have valve guide issues (and it is more likely than on an SC). If you talk to the owner ahead of time, tell him you want the car stone cold when you get there. I.e. parked in the garage. Then have him start the car for you and watch the tail pipe. A little bit of blue is normal, but if the guides are really going out, you'll have a lot of thick smoke that will take minutes to clear up.
That's really all that I can think of, besides rust. And there I am no expert, since I live in CA.
A PPI will be mandatory, of course, where you can have a look at head studs, compression and the play in the valve guides. But that's old news and nothing specific to the Carrera.
George