My car went through 4 timing belts in 2 years thanks to faulty cam gear teeth.
I had a problem with over-heating and replaced the thermostat first, then water pump, then radiator. Now all is well.
My rear calipers had frozen and needed to be replaced along with the rotors.
The valve cover gasket has always had an oil leak. Along with a tick tick tick noise that is non-stop.
Driver's seat has busted at shoulder-blade level twice and have had to replace driver's seat.
Window switches are junk, only 1 works.
Headlight switch is a big problem. I have replaced it 4 times as they keep heating up and smelling like burnt plastic.
I have replaced 2 mufflers as water gets built up in it causing rust.
My shocks are horrible.
Both rear doors hardly open, unless you crank up wards on the door while opening.
The "quattro" 4X4 feature is the only thing that keeps me in love with this car. It has never broken and always performs well in the Washington snow!
The car has a strong and snappy engine... gotta love the 5 cylinder!
The frame and feel is very solid.
Your car's nearly 20 years old, so nothing surprising about the niggles, but the quattro drivetrain is definitely robust. I used to have an '85 80 GTE and a few things needed doing to it -- but only because of age, not quality, an electric window motor being one of it.