I bought a 67 Mustang a while back and at the time I didnt know the big question to ask, does it leak? Anyway, it has been a very frustrating issue for me. I love the car, it runs great, I have done many modifications like adding power disc brakes and electronic ignition, etc…. The interior needs work and I really need to address this leaky cowl. I have bought the plastic inserts but I guess it is to far gone for them to work. I understand the box needs to be patched or replaced. Lots of $$ I really dont have to spend right now. I just thought I would ask if anybody might have another solution. Is there something that could be sprayed into the vents that would seal it up? Maybe like the material they spray into the bed of pick up trucks.