On several occasions, my '91 M5 has "popped” out of reverse as I backed out of the garage in the morning. The car has almost exactly 100K miles. The clutch was replaced at 80K, but I have had absolutely no problems with the transmission. (Well, except I had to fix a small leak on the top of the case.) Is there an adjustment that can be made to the linkage? Any suggestions for a possible fix?