ACE is the Place,
go to where they have the foam sealing section then look for the gray closed cell or rubber foam with sticky on one side this foam will only work on S4 and later cars. Its about 6.00 but there is enough to do both tail lamp housings you may have to use a card to assist in feeding the foam into the PU cover.
Wipe the edge down with alcohol so the foam will stick,
and the foam sits about 1/4 inch back from flush of the lens

 

thanks..so I'm sure I understand, this foam is used in lieu of replacing the designed seal? I ask that cause if my TB issue allows me to "survive", then I'll be having the car completely stripped and repainted the factory color...meaning I'd probably replace all of the seals. This sounds less expensive.

 

Ah no Frank the addition of foam seal to the external edge of the light housing on an S4 tail light is to keep water out of the well that the light fits into, the wells can fill up with water if the car is parked nose down
For your car since you have an OB style of tail lamp IIRC there are foam seals available for not much much they are round and fit into the lens groove

 

Thanks....

 

From the 928 FAQ topic posted at the top of this forum:

https://rennlist.com/forums/2375680-post35.html