With my second Benz (a '90 300TE), I'm tempted to try to learn to do a little bit of my own work. I need a new radiator installed (the inlet neck cracked), and both headlight doors are cracked. Are these jobs that anyone armed with the M-B service manual and a free afternoon can be confident with? Any tips on places for good pricing on OEM parts?

The radiator is a fairly difficult task for the individual to do at home because of the risk of transmission leaks or coolant leaks. These leaks can cause severe engine or transmission damage. The headlight rims are not very difficult to replace yourself and are readily available through aftermarket suppliers. Just take your time and don't "force" any of the plastic - it is known to break. A sidenote, we are going to try to add a parts section to mercedesshop for people just like you (let us know what you think).