Batboard

I'm in the process of installing a radio in a 1997 Dakota. The radio is under the driver's seat. I have already run power and coax through the firewall. I also need to run coax and power to the rear bumper. I should have no problems running the cable underneath the truck once I get it out of the cab, but I would like some advice on the best way to get it out of the cab.

Anyone know of any existing holes/grommets/etc I could use?
Any tips on drilling through the floor, if I need to? It looks like it might be a double floor - I'd hate to drill through anything that might be in there.
Would I be better off just going forward through the firewall, then down and back?

BTW, it's the extended cab version, bucket seats, with the center storage console, in case it matters...

Ok well different truck but it may apply to you. In my '73 Ford there were some grommets behind the main bench seat on the floor. I poked a hole in one (then sealed with silicone) and routed a cable through it to my bumper. I'd just slide underneath it and start looking for rubber grommets. That's also how I found a spot in my Explorer. You'll find something

There should be a rubber body plug back there that you can run it thru...

I know of a similar body style Dakota that had wires run out for an antenna and lights thru a factory hole, I just don't know where.