I had a minor fender bender with the 2007 R320 CDI 4Matic, and took the car to the body shop. They took out the headlights to do their work. The clear plastic shells, after 11 years, were UV damaged and foggy.

For an extra $150, they sanded the clear plastic headlight covers down to 1500 grit. Then they sprayed them with clear coat UV protectant. This usually goes on top of paint as the last coat, to prevent sun damage.

The clear shells are now absolutely clear and as perfect as they were when new.

The shop said this fix will last 10 to 15 years.


While they were out, I took them home overnight to clean the reflectors. The low beams were quite dim. The low beam halogens are in the cylinder in the center of the shell, it has its own lens, inside the shell.

I took the halogen bulb out, and made a tool from a wire coat hanger. I wrapped a Windex pre-moistened wipe around the tip of the tool and wedged it into the cylinder through the bulb hole.

I had to carefully bend the tool as it was inserted, to make contact with the inside of the small lens. As I wiped the lens I could easily see the dramatic improvement as it was cleaned. I swirled the tool around inside the cylinder to also clean the reflective surface in there.

With, new extra-white halogen bulbs ($60/pair), the low beams are as bright as they should be.

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1st MBz: 1982 300SD
2nd MBz: 1987 300SDL
3rd MBz: 1995 S420
4th MBz: 1987 190DT
5th MBz: 1984 300SD w/1983 300DT engine
6th MBz: 1999 C230k I'm 3rd owner, got it w/57,235 miles.
and manages Mom's 2007 R320 CDI