My 300E started dying on me in a completely random fashion. The research I did said it's probably the fuel pump relay. I replaced that to no effect. A little more digging and it was clear that my wiring harness was toast and it was probably the cause. That was replaced and everything was fine for 200 miles and then back to the same problem. The mechanic who has been in the biz for 30 years and owns the shop says it could be anything, but doesn't seem to know how to diagnose the problem. I have to believe that with all these cars still out there someone has had the same problem and figured out how to cure it. HELP!