I was poking around on MBworld.org and came across this site www.oempartsdirect.com that has OEM Mercedes parts for a decent price. It's pretty good if you're looking to upgrade your intake to a E500 intake as it's only $215 for the airbox itself. You can even get the E55 intake for just over $300.

I know someone here has an AMG intake on their Limited and an E500 airbox

Figured I'd let people know

PS...for the E55 stuff you need to look in 2005 under Engine -> Air Intake -> Air Cleaner