I got done (for now) sound deadening my truck today, and when testing, I noticed there was still a bit of a rattle coming from some unknown location. I put my hand on a bunch of metal panels, sat on the box, nothing. Finally, I decided I would wait till daylight to really diagnose the problem. Later, I put a shirt over the port to see how much air was moving... The sound stopped. I removed the shirt, it started again. Did it a couple more times and the same thing happened... Am I missing something, or do I just need to dress up (lol) my box for it to want to work properly?