I have a 2004 supercab and just bought an infinity 6 channel amp to run all the speakers and sub. The sub is going under the drivers side rear seat but I can t find a place to mount the amp as it is about 20 or so inches long so the passenger seat is out of the question. I guess that behind the back seat would work but I am un sure as to how to get back there. Any suggestions? The amp wont fit under the back seat either because of the sub box.

 

I think I remember looking into this before I bought my stuff. That infinity is a nice amp, but it's pretty darn bulky.

If you have a power sliding window back there (like I do in my FX screw), a 21" amp won't fit without bumping into the seat cushion or unless you can relocate the window motor which isn't necessarily possible. There's just a tad under 2.75" of clearance between the back of the seat cushion and the rear wall depending on how high you mount it off the floor and where the seat brackets stick out. You might have to cut or remove the rear insulating pad which takes up about an additional 1/2" of clearance and forgo some cab quieting.

The biggest amp that would fit comfortably in mine was an Alpine 5-channel with the cover removed or a JL 300/4 on the passenger side. I ended up with the JL. I'm trying to add a JL 250/1 on the driver side, but it looks like I have to relocate some kind of control box. A 500/1 wont fit at all :-(

 

I relocated both my power rear window motor and the other black box to fit 3 amps behind my rear seat. Check out my gallery.