regarding the source of 'selfleveling susp. inact' problem, mine had the same problem and just had it repaired by dealer. the problem is a part called 'air supply control unit' which controls the rear suspension failed. Dealer replaced the part and everything backs to normal. the ride becomes more comfortable than before. the part costs me around US$200. Before the dealer replaced the part, the warning light had displayed in the dash board from time to time, but not all the time. so do not think it is ok when the warning light goes out. once the warning light comes up, there must be some problem in it, so get it to dealer for inspection.

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--2004 E53 X5 4.8is - ECE version; right hand drive; Located in Hong Kong; ext. black sapphire metallic; int. leather black; adaptive dynamic bi-xenon headlights; 16:9 onboard monitor w/o navigation; 20" genuine BMW Y-spoke 214 wheels with Bridgestone Dueler H/P Sport tires; Int. rear view mirror w/ compass.