I had my SES light come on in my 2002 M5 last week. It didn't have any effect on the cars performance(limp mode, etc). It went off 4 days later. I had already scheduled an appointment went it came on so I took it to the dealer anyway. They pulled the codes and both sides of the Vanos needs replacing! 13,000 miles on the car. Luckily it is still under warranty. Just an FYI to follow up on the SES light even if it doesn't remain lit or the car doesn't display any additional problems.