I made a bet with a friend that I could pull 140 db flat on a $500 dollar budget using only rampage gear

He has spent $4500 on his stereo and only pushes high 141's
Im Pushing s**t up a hill I know, but worth a laugh

Plus I'd love to see the depressed look on his face if I push close to what he is on less than a 1/4 of the budget

Been searching around and I can't find any sign of rampage gear anywhere!
Super cheap auto used to stock them but seem to have tried to move up in the world and cut the rampage sales

Anyone know where I can find what I'm looking for? Or know of another brand that make absolute rubbish?
Cheers Paul