But any car that you look at with a view to buying is likely to have at least a few of these faults.

You'll also find that this list is fairly accurate for the Coupe GT too... 

Rust
Seam where the rear panel joints the boot floor
Spare wheel wells in boot
Boot hinge points
Seam at the rear of the cabin floor.
Rear wheel arches, especially the drivers side on UK cars
Rear of sill near the arch
Underneath the body rubbing strips
Front lower part of front wings
Door hinge points on A pillars
Windscreen surround
Sunroof panel (and it may well be stuck in the closed position)


Drivetrain
CV joints and boots (there are 8 of them)
Rear Diff seals
Diff locking mechanism (actuator on rear diff)
Prop shaft CV joints and centre bearing
Gearbox driveshaft ouptut seals

Clutch
Slave and Master Cylinders (especially if the car has been left sitting)

Brakes
Master Cylinder (especially if the car has been left sitting). Dificult to change
Rear Caliper handbrake mechanism
Proportioning valve
Rear disk splash shields

Steering Suspension
Strut top mounts. Especially front ones.  
Shocks(watch out for original dampers, mine had done 188k, no oil at all......)
Springs (breakage)
Rear Tie rods
Front tie rod adjustment, tie rod ends (rusts solid)
ARB bushes
Wear in rack
Wishbone bushes
Subframe bushes

Fuel
Noisy fuel pump
Rusted / split fuel lines at rear of car
Injector seals

Engine
Water pump / cam belt
Valve stem guides and seals
Hydraulic tappets
Breather system cleanliness
Drivers side engine mount


Exhaust
Exhaust manifold : studs, cracks (caused by bad engine mount)
Exhaust downpipe

Other
Door handles
Electric window mechanisms
Headlight adjusters
Black rear lights and coupe strip
Drivers seat
Water deflector
Boot lid struts
Central locking pump


Electrics
Headlight reflector corrosion
Headlight switch
Headlight wiring and dodgy relays

Also have a look at http://www.kvquattro.com/buyersguide.html