No Instatrunk, I got a Smoking deal on a JL Sub(Craigslist,going to pick it up this afternoon), Its not marine but i don't feel its necessary, It has a injection molded plastic cone and Rubber surround. If the speaker is good im going to buy PBR300X2 Micro Amp, Its about 300watts RMS with a footprint of 1.53" x 4.25" x 6.75" For low end. Im Running nice Boston Coaxials in the front and some crappy Walmart pioneers in the sound bar, im thinking after i upgrade the Sub/Amp(I currently have two rockford 8's they just dont do the job and take up all the room in the "trunk") I'm going to do the 6.5 mod to my soundbar and run a set of Boston Components with Rockford PBR300X4 for the door Speakers, All this i hope to have packaged in half the space behind the rear seat. Im working on ideas now for the Speaker enclosure, Im thinking about using MDF(I know about the moisture issue) but coating the entire box with either a Polyurathane or Fiberglass resin. Then hitting it with the thickest bed liner(open to recommendations) i can shoot out of a can. Then Top it off with a ABS Plastic cover over the top of the box and Amplifier(s).