I plan on using some rubberized undercoating on the inside of my car as a cheap way of sound deadening. Ive seen pics and read threads on it and it seems to work pretty well, however I have a few questions about it. First off, if I put it around the front foot wells of my car, will the rubber melt from the heat? Secondly, the mid basses I have in the sail panels of my car makes the skin of my car rattle slightly when I have it cranked up, would spraying some undercoating into the opening there and hoping to get it in between the panels work or would it have a detrimental affect on the sound coming from the speakers? Thanks guys!

 

I have mine coated from firewall to tail lights and don't have any issues with it melting.

Also for the sail-panels, I have in there coated as well, and it improved the response of the speakers actually and helped reduce some of the resonance. Also with the sail panels stuff the upper and lower portions with fiber-fill (pillow filling) and make kind of an enclosure with it; this will also typically help with the performance of the sail-panel speakers.

 

Will that help with panel rattling also at all? I dont hear it on the inside of my car, but when im outside of my car I can hear it, and I dont want to pull up next to someone and all they hear is my car rattling from my music. Some people may think thats cool cuz it means you have your music up loud, but to me when people pull up next to me and I hear that, i laugh inside. So i dont want anyone laughing inside at me.