Oh hell! I have precisely the same problem and took my car to the Merc dealer today, quietly confident that they'll find the right one easily. It started well enough, "well they look like Mercedes nuts" he claimed. However, no luck. All their nuts were too small (or more the the point, mine were too big). He said Merc ones are 17 mm, so mine must be 18.5 mm. I'm going to take it to a Chrysler dealer on Saturday (wish me luck), but does it sound like mine are not standard? I have four regular bolts in the boot. Is that normal?

Car ownership really is a trial sometimes...

 

I have several that could be for sale if anyone interested. Pm me and I'll post photo.
Postage from Sweden. Btw, good luck in euro2012. I rooted for england!!!

 

What a nice Crossfire owner

 

A pin socket may work but probably at it's limit going past 90ft/lbs. If all else fails, I would plug weld a nut on the end of the lugbolt. Just make sure to put your ground clamp on an adjacent lugbolt

 

Just hammer on a under size socket. Hard to get the nut out but that will do it.

Good luck

 

Won't work, they've got spinning externals bits. Also made out of hardened steel so cannot be drilled. Welding is a possibility, but could knacker the wheel and will take time.

This is such a headache, bloody cars!

 

Go to your local welding shop and ask them to plugweld a nut using a mig welder. This is a fairly easy task

 

Can you take a picture of the nut?

 

Here you go, thanks.