Getting a wire out of the cab

I'd like to find a good spot to bring wires out through the back of the cab of my '04 Ext Cab. Anybody know where I might do this? Grommets, plugs...etc.
It looks very sealed with a quick look from below.

Thanks,
!

I'd like to find a good spot to bring wires out through the back of the cab of my '04 Ext Cab. Anybody know where I might do this? Grommets, plugs...etc.
It looks very sealed with a quick look from below.

Thanks,
!

When we run nitrous lines from these trucks, we use the knockout plate on the passenger side. When you look under the truck, you'll see a circular plate that is obviously a different piece that the rest of the truck. That plate can be knocked out and drilled. Then use a rubber grommet to fill the hole and allow the wire or wires to run through tight.