My 1997 E36 M3 has recently developed an annoying/troubling problem. It's sometimes difficult to shift into reverse, 1st or 2nd gear. This has been going on for a while but recently it's gotten much worse. Yesterday, I was in a parking lot trying to back into a space and I could not shift into reverse for the life of me. Some cars started coming down the row and I decided to forget it and drive around to the next row instead of blocking traffic. I tried shifting into first and could not. I tried second; no good. It shifted into third with no trouble. I drove around the row and shifted into 2nd and 1st along the way with no trouble. I tried to back into a space again and, once again, I could not get into reverse. Cars started piling up again so I decided to drive off once more and the same sequence of events happened, no first or second, drove off in third. All in all I went through this three times. Later that day I got in my car and drove off and all the gears shifted normally. As I continued to drive, first and second got harder to shift into and I had a hell of a time getting into reverse to back into my driveway. Anybody have any idea what's going on here?