Sepang International racing track (home of the Malaysian Formula One and Moto GP races) is adjacent to the airport- you might even see from the air on approach. They offer tours of the facilities for RM50 when there are no races taking place. I've never done this but would probably consider it if I were in your shoes:
Circuit Tours : Introduction | Sepang International Circuit, Malaysia
Sepang reputedly has some beautiful beaches too which might be worth asking about. If motor racing and beaches aren't your thing then ten hours is plenty of time to catch a bus/train to Kuala Lumpur and hang around the city (if memory serves me right it takes around an hour each way).