This may help I had the same problem (E12 error) and tried various suggestions such as disconnecting an reconnecting, cleaning the lens etc. Then I noticed that the CD wasn't actually spinning as it always ejected in the same position.
Solved the problem buy removing the radio from its console leaving the wiring connected. Removed top lid - (need torx screwdriver) then with CD inserted and CD button pressed gently turned the centre plastic location piece with a screwdriver after a few attempts it sprang into life and now works perfectly again.
It's worth a try. - Beware of laser beam!
Raymondo
April 2010