Getting an Audi

Well I'm getting an Audi from my moms cousin...I dont know anything about it. I'm getting it for around 700.

Is there any common problems within the Audi line of cars? If so, what are they?

Thanks for any help.

Well I checked it out on monday.

Its a 1993 Audi S90.
little less than 115k miles.
Runs good. Few minor things. Needs new tires etc etc but they might be doing that for me.
Also, its great. I have pictures...shitty quality but it works.