THe BMWs have a service countdown indicator. When you start the car, you will see a set of bars. It starts with a number of green, yellow and red ones. When it gets down to red ones only, you need to perform service.
The service goes: Oil Service, Inspection 1, Oil Service, Inspection 2, then repeat. So every other service is an Inspection.
Inspection 1 is a good bit less than Inspection 2. But both should be done as indicated. The service interval is variable based on your driving, but for the 99/00 cars, it is about 9,000 miles. So an Inspection every 18,000.
'95 Alpine M3 LTW
'00 Dakar M Roadster
'02 Topaz M3
Red/White SRF #4 (Chassis 561)