Now I know why they call it Thunderform!
Crutchfield Customer Review (What's this?)
I put this custom formed sub in my 2008 Silverado Crew Cab. It fits perfectly under the back seat, drivers side. I'm powering it with a JBL - GTO 5EZ amp. This thing hits so hard, it feels like someone is kicking my seat! It's got great tight base that will loosen the fillings in your teeth! Just about as easy as possible to install and a very clean, sanitary look in the truck.
Pros: Custom fit, kicks like a mule and great sound