well this started when i built a custom box and amp rack for the trunk of my sunfire. i built it so the box is on the pass. side facing the back of the car and the amp rack is right next to it, all wires are run thought the back of the amp rack. Now when i put the box in before everything was fine. i took it back out and carpeted it and put it back in and now the sub will randomally go "pop" and stop workin then start again. Like every 3 or 4 or 5 or 2 bumps it will pop and shut off. We thought maybe the sub was bad so i switched the sub out for aother sub excatly the same thing and it stoped doin it. So the next day (yesterday) i took it and for @!#$s a giggles we meterd it and i hit a 131.4 Db. Then today i went to show it off to 2 of my friends and i opend the trunk and turned it on and it started to act up again so i shut it off and walked away. about an hour later i come out and drive off and it hasn't happend since. So what im thinking is everytime i have my lid open the sub acts up... WTF?? what would this have to do with it tho?

The sub is an Alpine Type-E 4 ohm and the box is 1 cubic foot sealed. the amp is an Rockford Fosgate P2002

Ground issue? Wires pinching anywhere?

nope checked and rechecked everything