Found this on an M5 site, interesting and scarry. I have never read anything like it so assumed that it has not been posted here:
http://www.bmwm5.com/vbulletin/showthread.php?s=83d72c4dcd4fe5e6bd57ddb610987db5&threadid=28464
http://www.bmwm5.com/vbulletin/showthread.php?s=83d72c4dcd4fe5e6bd57ddb610987db5&threadid=28464