Welcome to the Mercedes family. How many miles on the C280? I would personally not have the fuel injectors cleaned. I would recommend going to the auto parts store and buying Techron by Chevron (about $8) gas treatment instead. Then, fill with premium fuel (as always) and it should clean any deposits on your injectors after a spirited interstate drive.

On the tune-up items I would encourage you to do them yourself. The coil packs are about $60 each (you have 3). These are easy to replace. The wireset is about $60ish for your car as well. You will almost always pay 3x as much at a shop with labor. These are easy things to do especially if you have a great forum like this...

Your wiring harness is very expensive for some reason. $1000++ There are several part #'s in the system, it would help to have the last 7 of the VIN. I would gently peel back some of the insulation and inspect for cracking. Good chance your has been replaced especially if you are well over 100K miles. On a low mile car, just no easy way to tell without a part # or visual inspection.

On the turn signals, the blinkers don't blink when the headlights are on? Has it always done this? Try a fresh set of bulbs all the way around on the blinkers (they are cheap). You could have a bulb issue, or a combo switch issue (blinker stalk on the column). It's easy to replace if you have the right tools (i just did one last week). Your part will cost about $121 ish. Airbag and steering wheel must come off to replace this switch as well as the lower dash. Took me about 1.5-2 hours tops. A shop would probably charge $300-450+ for this job.

Or, you may have a bad headlight switch. But, I doubt that. Start with the bulbs, pull each out and inspect the sockets. I say start with new bulbs because you may have the wrong one(s) in there to start with and again they are cheap.

Keep us updated and send along some pics of the C280. I had a '99 C280, and it was a great little car... Enjoy...

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