I had a similar scraping experience, with my 97 E420, while pulling into a parking spot at PEP Boys. I didn't get a coolant leak, just the fan scraping noise (and a bad A/C condenser, I think).

Looking back on it, I wish I would have realized that the car had never scraped the curb in that lot before. The reason it did was that the spring perches were failing, and the front end of the car was lower than it should be.

While your car is still up on the lift, have them look at the perches. Unless they are MB guys, they wouldn't have noticed. You may need a welder to fix the rad support, and he may be able to fix the perches as well, if you have that problem.

Plenty of material on these forums about the perches.

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1996 C280 289K Traded
1997 E420 167K Traded
2001 S430 240K Traded
2010 E550 4matic 80K
2000 GMC Jimmy 198K Gone to Boneyard
2003 Camry LE 196K
2011 Mazda3 i Sport 31K