I went to pick up my car and it wouldn't start. Try'd a new battery still nothing. Changed the DME unit under the drivers seat and she started right up. ALWAY CARRY A EXTRA ONE IN THE GLOVE BOX. From what ive been told you could be driving down the road and if the DME goes bad, the car just dies. Hope this helps.
http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=911-618-154-00-OEM&catalog_description=DME%20Relay%20%28located%20und er%20driver%20seat%29%2C%20%39%31%31%20Carrera%20% 28%31%39%38%34%2D%38%39%29%20
Rob