The same thing happened to me. I ordered 2 radiator hoses and a new thermostat. They were at my house in one day, and I did pay for over night shipping. Well actually I didn't pay for any shipping since Fastlane was running that special for orders over $25.
Mike I think the reason you and I got our parts so quick was because "Fastlane" parts come from a supplier here in NJ, Flemington NJ to be exact. When "Fastlane" came on line I noticed that the online catalog was exactly like an outfit called "Megaparts.com". I e-mailed the Mercedesshop guys and they said it was the same supplier. I had in the past ordered from Megaparts and their address is in Flemington NJ. BTW, generally the prices are better going through "Fastlane" vs. Megaparts. For me I benefit from ordering through Fastlane because that way I don't have to pay any salestax, since Mercedesshop in located in Georgia.
1994 MB E320 Coupe (199,500 mi)
1992 MB 190E 2.6 (173,000 mi)
1983 Porsche 911SC (148,000 mi)
2004 Volvo V70 2.5T (198,000 mi)
President of CT/Westchester Section