Since the others are targeting the engine area I'll point you to the odd ball stuff people never think of until it breaks. Front wheel bearings, new brushes and voltage regulator unit for the alternator. If you have not replaced it do it now the radiator, over flow bottle and the heater control valve. The plastic gets brittle over time and snaps at the wrong time. If you have the money and time replace all the bushings front and rear. With 200k the bushings are shot and should be replaced. This will tighten up the car a lot and make the fun to drive factor go up. BTW I changed the rear wheel bearings at 300K on mine. When I pulled the wheels for the front bearings they were close to shot and the brushes were almost gone in the alternator at 200K.

1987 745T M46 318,500 miles
SAAB APC Boost control 14 psi
Bilstein HD's, lowered,
U&L Chassis braces
25 mm sways and Hydras