cracked seam high corner foot well behind dash
sub, my car has been leaking for the last year when I got the engine rebuilt, and after it was hit in the right rear corner while on the trailer driving it down to get it built.. in NYC before the GW bridge...(hand), the van went over the trailer and hit the back light.. he was trying to make a gap that was only about 4' long.. wtf.. but anyways, mine has been leaking a lot since then in front right and rear pass side.. and my brothers has been leaking about the same in his msp for the last year or so.. has gotten worse lately.. so so happy I found this thread.. didn't wanna take the dash off at all, so going to see what I can get to soon, it's raining here tho for the next week right now..
hope all goes well
Check your body seams. After an accident, and over time, they tend to crack. I have the same problem and just picked up some 3M automotive general purpose sealant. I found the crack just above where your feet would rest on the passenger side (US, left hand drive). It is right as the body goes up towards the dash. Also, not sure if it's been covered, but check for any missing firewall gaskets. I had one missing, because the PO thought he needed two subwoofers in the back- both factory (MSP) and another. After the drainage channels below the windshield (on the outside) were clogged, it overflowed through the missing gasket.