I sold my C55 in large part due to the ubernanny electronics. You can defeat the system by putting it in dyno mode as mentioned above, but as soon as you cycle the key, ESP regains control.

Cool car but you are stuck with the nanny.

I concur on the warranty, you took both barrels to the chest on that one. You should go get a refund. You can get good warranties for as little as 1000, 2000 on the high end.

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1981 300TD
2005 C55
2004 E500
1999 ML430
1992 400E
1998 C43
2001 SL500
1988 300SEL
1986 190E 16V
1991 190E 2.6