No rust on the body (aside from the odd stonechip spot), but there's some holes on the inside of the doors.
Boot refuses to unlock when central locking is activated on driver's door, however you can lock/unlock the whole car from the bootlock. Very odd.
The driver's seat has worn through on the side squab - this appears to be a common fault on 80's German cars. New material is still available from BMW - impressive, but not cheap.
Inspection light is continually on - batteries are dead on the Service Inspection PCB.
Front door panel cloth had shrunk at the edges - rectified by dismantling the door panels, stripping the cloth from the backing, stretching, and stapling.
Stereo is not mounted correctly, so it will pop out to meet the gearlever during hard acceleration.
Brake pad warning lamp is constantly on - suspected duff sensor.
Gearlever tends to vibrate in second gear, but there are no problems with shifting in and out, and it doesn't jump out of gear.
Car has recently developed a recurring misfire, and can be hard to start from cold - suspected duff HT leads, although I did spray the engine bay with Gunk to clean off the dirt, then forgot to cover the plug leads when hosing off. WD-40 sprayed around the plug leads appears to have helped, but the car still hesitates at around 4000rpm under hard acceleration.
A very rapid car, although thirsty (20-25mpg average), and handling demands serious respect in the wet.
My 528i is unusual as it's a manual, and has a Getrag close-ratio box at that. Reverse is where first is on a normal gearbox, and first is where second would be. There's no lockout for reverse, so you need to reprogram your brain before driving or you tend to take off backwards from the lights.
Car has M-Tec sports suspension (firm ride, but feels very solid on the motorway), sports front seats (comfortable, but driver's seat is worn), limited-slip differential, and an M-Tec steering wheel (great, but mounted too low, so you can't see the tops of the instruments).
Typical German engineering - car has 150k miles, but no interior rattles, minimal wear on steering wheel rim, pedal rubbers and gearlever. The car has a full service history, so I had no qualms about buying.
Roomy interior - rear seat resembles a sofa! Beige interior has cleaned up really well, rear seats and carpets are like new.
One potential downside - the car has the original TRX metric alloy wheels, so getting decently-priced replacement tyres may be difficult.
I agree with the TRX dilemma. You are better off obtaining used 15" or 16" OEM rims, or aftermarket with correct offset. Then you'll have a larger selection on tires to choose from. The cost will be the same as if you decided to, but new TRX's on it.
I found the economy to be excellent as long as you werent stuck in traffic, but then I had the taller autobahn gearing and that was only when using a sensible right foot.
In the boot, there is an adjuster for the central locking.
Try to adjust, and the problem with the central locking will disappear..