So there's a leak in my trunk and I can't figure out where it's coming from. The car is a 2006 M3, no spoiler on the deck and the deck isn't where water's entering. There's dampness on the sheet metal just inside the lip of the trunk on the driver's side near the center line of the car which follows the contour of the sheet metal all the way to the side behind the wheel well where it forms a drip and hits the side of the interior and rolls down onto the carpet. I've looked around the outside lip of the trunk to see if there's a tear in the seal, which there isn't, and the only other access I can see is either under the rear glass or through the trunk release cable hole I've felt the sound proofing pad that's visible through holes in the body work of the trunk and it's dry so water isn't entering the cabin.

Are there any other holes in the sheet metal around the trunk that I might look at or would I be better served by taking the car to a body/glass shop to have them give me their opinion? I'm personally at a loss since I can't see where the water is actually coming from nor any likely suspects for the same.