I went out & purchased 4 of the 5M-20 bolts which are exactly the right size for the rear plate. I put 3 of them in to find the 4th would not catch the threads at all. It appears some asshat reamed out the 4th hole.

What options do I have? Putting in a bigger bolt makes a visual mismatch vs the proper 5m-20's as the bolt head generally increases in size.

 

Here a couple of suggestions.

1. Get a tap for an M5 size thread from a hardware store and try to re-thread the hole. It might work.

2. If that doesn't work, as I recall on my car, the license plate mounts to an aluminum adapter plate that is screwed onto the rear hatch (I have a wagon). If it's the same with yours, you can buy a new adapter plate.

3. Instead of #2, you could always get an M6 tap and re-thread all 4 holes to the slightly larger thread and buy matching stainless steel screws. Interestingly, I recall my car came with Allen head screws instead of Phillips. I've never seen that before.

Good luck.

 

Do what i did and found a nylon top hat just the right fit for the hole .Or the end of a rawlplug it worked for mine .The original ones are rivnuts ,they fitted them with a hand tool .Put a rivnut on the tool put it in the hole ,then you pull the trigger and it sqashes it as you pull the trigger.This is then use to screw you bolt in to .

 

1. Won't work, hole reamed out larger
2. I don't have an adapter, anyone have a picture?
3. A bit worried about taping plastic, perhaps the plate adapter will solve my problems

 

You can install mounting plate 1698170211 (Mounts directly to trunk lid, holes should align and should be able to use larger screw for one hole, license plate will cover it.) + 0019904236 screws to mount license plate. But 1698170211 new MSRP is $65. If you decide to do so, for peace of mind visit dealer to view part, your model year did not deliver with mounting plate.

 

I found this P/N 1408100411 when doing a search, wonder what the difference is?

 

1408100411 = wagon.

 

easiest and cheapest way to fix your problem...teflon tape.

 

Best option I've ever seen:

http://www.rhoplate.com/Products-MB.html

...and I just found that someone else on here beat me to the find: https://mbworld.org/forums/c-class-w...relocator.html

....or this James Bond special!
http://www.autosportcatalog.com/lice...-transport.cfm

found here as well: https://mbworld.org/forums/c63-amg-w...te-braket.html with more pics