Problem: Z3 trunk gets soaked everytime it rains or washed, water condensation in trunk...
Old style trunks:
(96-99 BMW Bulletin -German)
Sun, 29 Oct 2006 Harvster writes on Z3 Rides email list
This is for a 99 with the old trunk style:
Your problem is a worn gasket that seals the third brake light. The gasket part # is 63 25 8 389 735
There were two screws to remove. Do not let either drop into the trunk top. You will never recover it and it will rattle. Remove the wire harness. The light is held on with plastic clips integral with the light. Snap out the light and replace the gasket. You might want to smear some silicone grease on it for better sealing. When you replace the light, make sure you snap in all of the plastic clips. The screws will not do this. You have to
use finger power. When they are all snapped in, replace the screws(don't drop them) and plug in the wire harness.
Sun, 07 Jan 2007 Brian W writes on bmw-z3 email list
Regarding the third brake light, while this is not going to help in the casewhere the plastic is broken, be aware that after that area is disturbed, unless the person is very careful, the gasket can easily be compromised. It can be as simple as a speck of dirt caught between or rolled over at an edge. The good news is that it usually doesn't have to be replaced. Just remove the brake light with a Torx, T8 I think. Carefully clean the gasket and the surface around the outside of the brake light and re-install. Listen for a "click" when the two separate plastic pieces snap back into place.
New style trunks: (after 99, such as BethR's '00 Z3 2.8)
to +Zero HP/Making it Pretty
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