Have you checked MSD's website? www.msdignition.com From what I know, the 6 series is the most popular, but requires a distributor, and says in the instructions that it will not work in distributorless cars. They do have digital boxes, but I think it would be a nightmare to get their computer to deal with the original mercedes computer.

My opinion would be to replace the plugs with quality replacements (check the gap), check the plug wires, and make sure the ground wires are clean and tight. Also do a search for idle hunting, might be an issue with a dirty MAF, or the throttle body.

Chuck

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2000 C230 Kompressor "Frosty"

2007 PT Cruiser
2001 VW TDI Beetle
1999 Landrover Discovery II
1971 Corvette

Gone: 97 Cabrio, 83 240D, 93 VW Eurovan, 95 Volvo 850, 93 Chevy Astro Van, 77 VW Bus, 99 VW Jetta, 74 VW Bus