I have a 1991 735iL. I experiece a fairly loud scraping that sounds like the drive shaft is scraping the heat shields under the following conditions. 1. Drive at highway speeds for several miles. 2. Come to a stop light and site for more than 45 seconds. 3. Drive away and there is a loud scraping coming from about end of the transmission area. When I turn right the scraping is pronounces. When I turn left the scraping subsides. After driving for about 60 secons the scraping goes away. The last time the car was in the shop the mechanic replaced the transmission mounts. That did not do the trick. I live in Florida and do not encounter this problem during the cool winter months.