I had a most annoying problem. My high mounted third brake light created quite a distraction in my rear view mirror at night. Light washed both down the window as well as internally reflected light off the window landed on the rear deck.

At first I suspected aftermarket hijinx by the PO. However, after questioning my dealer and Indy and looking at other '98 S70's, I discovered my setup was OEM. The light housing mount is non-adjustable and it is hard plastic. There is no OEM flexible seal to press against the window.

My housing sits 3/8" from the window, causing the two leaks described above. I don't see how this is supposed to work, because the window install would have to be perfect to not have a leak.

I used a piece of 1/8" adhesive door frame gasket on the housing, which stopped the wash. Then I discovered the internal reflection (!). Another piece of the same gasket, adhered to the window and offset, stopped the reflection. Completely eliminated the problem.

I believe the 850 housing had a flexible seal. I can't believe the S70 didn't. My Indy, who has wrenched Volvos for years, says he can't remember anyone complaining about this...