I have seen a few E46 on the track, last one being Walrus Lord's 330i. Don't think there is any problem after the track and generally Sepang is gentle to tires.
Before tracking, check your tires and get it properly inflated. Do a couple of warm up laps and then check the tire pressure again, try to run it slightly lower than the recommended tire pressure. The other things is to check for oil leaks, if the leak is bad and the management get to know about it, you may get fined.
Other than that, drive sensibly. If you a beginner, let the faster cars go through and enjoy the drive