Rear Suspention

What is your question?

I absolutly love this 1994 Lexus ES300.. I bought it in 2000 with 79K miles on it. I have done a fair share of repairs on it but I would suspect as many as with any other car of it's age. Timing belt, Tuneup, Alternator, Belts, O2 Sensors, Brakes,rear tortion or swaybar links, front and rear Struts, comlete exhaust sytem, except for Catylitic converter. My only problem now is a knock in the rear suspention, mostly noticeable just barly rolling and hit small cracks in the pavement or as driving in a grass feild parking lot. Just a small bump will cause a knock in the rear. Drives me crazy. I am sure it does it at highway speed but it is not noticeable because of road or wind noise, which in the vehicle is pretty minimal. The only other problem is a ABS brake light that will not reset, and an Air Bag light that will not go out. I am thinking fuse on the Air Bag but can't fine one.