I love my Kel-Tec Sub 2000 for a truck gun. It's a 40 S&W. It's hard to beat a pistol caliber carbine - high capacity magazines, cheap to shoot, decent muzzle velocity, lightweight, and since it's sholder fired, more accurate than a handgun. Oh, and it folds in half! Mine has a few mods from RLP and a Trijicon Reflex site that will co-witness the iron sights. I carry Underwood Ammo Xtreme Defenders 1400 FPS and 500 ft lbs Muzzle Energy (probably more out of a 16" barrel).Fun little guns and the 16" barrel adds some zip to the 9mm. Every Kel-Tec product I've seen seems to come about 95% finished with the buyer needing to clean up leftover mold flashing, smooth off rough edges, polish the internals, etc. IIRC, you guys can't get the good magazines i.e. the 33rnd Glock mags but I can recommend a couple of items if you can get them. The KelTec factory spare magazine holder if it will work on the 2nd gens (not sure and I don't see them on KTs website at the moment) and a rail section for a light plus there is a company called tacticool products that makes a slip over buffer tube cover, bolt buffer and a cocking handle slip over cover. The buffer tube cover fits nice and helps when it's cold out; the buffer seems to help recoil a little but the bolt won't lock into the rearward position in the notch if you use it. Mine is a 1st gen and folks seem to enjoy shooting it and it's always been reliable, even with the inexpensive Korean magazines*, but it just doesn't inspire enough confidence in me for some reason, I guess it's just a subjective thing regarding the way it feels.
*If you get the Korean mags, you will need to disassemble them, clean up any flashing inside, possibly smooth the follower, and replace the bottom with a factory Glock (they stay on better). If you still have any issues replace the spring with either a factory Glock or aftermarket such as Wolff.