Rims are on! Thanks again to all for the help and tips, especially gregs210 for the RAD bolt specs. Both the rims and the RAD bolts fit perfectly. I've driven them around for a week or so now and zero issues. I really like the look, IMHO they update the look of the car without looking too out of place.
Before:
New rims (from 2006 E350 W211):
After washing, nightime:
