Hello, I have a problem with fuemes inside the cabin of my 928 S4 1988. Nobody of the mecanics that I know and work on Porsches could find the problem. Had anybody out there in the Porsche world the same problem and know what the cause might be???? I would really appreciate your help, thank you guys...........

 

Firewall seal, rear hatch seal, door seals, inner shift boot, etc can all let fumes into the cabin.