My dealer story. (first time to dealer since I bought the car in Dec, maybe last time). Took my 300D to the dealer Friday to replace the turn signal switch. (Mercedes dealer in town) PO took car there for everything. On a recent trip to PA, after using the turn signal the wiper turned on intermittent mode. Had to turn on slow, fast, then off and problem would go away. Did this several times on the trip up, then while I was there the wipers came on slow speed continuously. Had to fiddle with wiper switch and leave between 1 and 2 position to stop wipers. Afraid to use turn signal to avoid starting wipers. So I did the quick fix for the rest of the trip. Pulled #2 fuse, which killed wipers (lucky weather was dry) but also killed windows and seats. No problem. Did not know about relay at that time. Had to pay tolls on I95 by the "open the door with the window up method and hand over money" which I see being used by others on occasion and is good for a laugh. Searching forums found the switch the likely culprit and seeing how wheel has to be removed, lower panel, etc. felt it was better to pay 2 hrs labor instead of all my Saturday (and maybe break something else, or not finish). So Fri afternoon went to pick up and start car and wipers run again low speed. Service writer and 2 techs come out and switch out relay and problem solved! Add one relay to bill. Maybe switch was good after all. But 13 years old and switch was always balky in the left lane change mode, had to make full click to get signal to turn on. Tech says "well you diagnosed so we just replaced switch" My fault I guess. Maybe they would have tried the (easier) relay first and not had to go into column to the combo switch.

Fun started Sat when I tried the horn. No horn! Worked fine when I dropped it off. Had to make a trip today and don't feel right w/o horn (once I knew it was inop) I figure I am out a few more hours Monday by bringing back and telling them they forgot to reconnect the horn and waiting for them to fix. Decided to dive in right then and pull airbag, wheel, and 20 min later it was all there and obvious. If I knew it was that easy to do I would have done it myself. As my dad always said, if you want it done right do it yourself. Back of wheel had 4 copper concentric rings, but only 2 contacts showing. Look at old combo switch they were kind enough to return to me..... 2 spring loaded contacts sticking out!! Now I am PO'ed. They must have had the car wash tech working on my car. I am still going back tomorrow and showing them their screw up. Doubt I'll get a credit back on the bill, but will ask. It would have cost them an hour to switch over the contacts like I did, but I would have had to leave the car 1/2 or all day. I sure am glad I do most all work on all my vehicles. I thought this job would have been more difficult than it was. Live and learn, and beware dealer service depts.!