71 ford maverick hot rod, upgrading stereo

I have a 1971 Ford Maverick with a built motor and a lot of other go-fast goodies. It's finally time to upgrade the 8-track, but I don't want to cut into the car. Orig. equipment was just an AM with a single 4x6 in the dash. I do not want to cut into the kick panels of this car, and the inner doors are solid steel. There's is no lower dash to speak of as these cars had "package" trays instead of glove boxes. I've already made a false cover out of an old AM face for car shows to hide the CD player, I'd like to keep this simple. I have a brand new Pioneer DEH-P4000UB sitting here that I got for cheap (yes, I'll be sure to disconnect my ground before install and avoid frying the jacket circuit) I listen to a lot of oldies (go figure) and rock. I'd like something with pretty good SQ. Here's what I'm thinking. Make a plate to mount two 3.5" 2 or 3 ways under the dash, angled slightly to give a L/R separation, and bolt them in the place of the existing 4x6, then two 6x9's in the factory rear locations, with a small sub in the trunk. What I'm looking at: P400-4 Rockford Fosgate Amplifier SPS-609 Alpine 3-way 6x9's 85w RMS (running off 2 channels) REF3022CF 3.5" 2-way Infinity 25w RMS (running off the deck) A sub running off the last two channels bridged? What I'm confused on is what would be the best size/resistance subwoofer to run on the final two bridged channels of the amp? How would that even be set up? And yes, I work at Best Buy, so I'm getting the cheap stuff cheaper and sticking to alpine, RF, infinity, etc for the sub. The car is loud (open headers) and full of vibration.

50 views and not a single suggestion, am I in the wrong place?

You do not have to cut your kick panels, you could simply build another set out of fiberglass and paint them or carpte them and as you are making them, set them up to hold a set of 6.5 with tweeters.  There are so many possiblities with that car it is crazy and you can keep it all virgin without having to cut a thing.  It would be nice to see some pics of the car.  Keep us posted.

Correct me if I'm wrong, but the way I read the specs its 4 ohm per channel or 2 ohms bridged? # 50 watts RMS x 4 at 4 ohms (100 watts RMS x 4 at 2 ohms) # 200 watts RMS x 2 at 4 ohms (4-ohm stable in bridged mode) # variable high-pass/low-pass crossover (40-400 Hz, 12 dB/octave) Can I run two 6x9s (one channel each) off this and just bridge two channels to run a sub? What does 4 ohm stable in bridged mode mean?

No that is not correct.  That amp will run 2 Ohms per channel or 4 Ohm mono.  Per each pair of channels.     Yes you can use half of the amp to run the 6 x 9s at 4 ohms per channel.  50 watts each.   Then you bridge the 2 remaining channels on a 4 ohm woofer that will be seeing 200 watts.  Or an 8 ohm woofer would yield 100 watts of output.   The part saying it is 4 ohm mono stable is telling you that the amp will run safely into a 4 ohm  mono load.  But it will not run 2 ohm mono.  Well it will but it's time will be limited.