I have a '70 510 and I decided it was time for some tunes for the first time since I've had the car. The problem I'm running into is where to mount the front speakers. I want to put them in the kick panel but not only is the existing hole to small but it I made it big enough there wouldn't be enough depth. They are 5 in speakers. I was thinking of trying to use fiberglass and see if that works but I have never used it before so I kinda unsure. Also if I were to use the fiber glass what kind of wood would I use too frame it.