If someone would be so kind as to design a single 12" subwoofer box for me. I've attempted to use various software, without success, and i don't want to build something that won't sound its best :). I'm trying to use as little space as possible in my trunk also. I need a blueprint so i can start cutting the wood and building my first box :) (3/4 inch MDF)

I think below is all the info one would need, if not, please msg me or post here, i got all this info from BassBox 6 Pro. I would like to build a vented or sealed design which is what i read is recommended for the speaker. I would mostly listen to it playing rap/hip-hop/dnb/jungle/trance.

The driver is a Alpine SWE-1242
Standard One Way Driver
Kevlar-reinforced pulp cone.
Santoprene surround. Dual Nomex spider.
Oversize parabolic dust cap.
Steel basket.
38 mm diameter. Brass former.
64 oz magnet. Vented.
Fs:31 Hz
QMS:9.68
Vas:61 L
Xmax:11.7 mm
Sd:490.9 sq. cm
Qes: 0.7
Re: 3.6 ohms
Le: 0.8 mH
Z: 4 ohms
Pe: 250 Watts

Thanks in advance.

Oh i forgot to add i'm gonna power it with a PIONEER 7100 M 250 Watts RMS @ 4 ohms

how big of a space are you looking to get it in... it would be nice to have the max height, width, and length you prefer... just take a tape to your trunk :)

If this is your first box then you would be a lot better off making a sealed enclosure, as they are a lot easier and more forgiving to airspace errors. This will also usually get you a smaller box. In this case for your music you are going to need a box about 1.3-1.4 cu. ft., so it's not going to be very small. Probably would have been beter off with a Type-R than the Type-E series.
The front of the box will have to be at least 14 inches just so that you can mount to sub, depth wise you are going to need at leats 10 inches so that you can have enough backspace for the voice coil to breath properly. If you take 1.4 cu. ft. plus .086 cu. ft. for speaker displacement, multiply by 1728 for 2567.808 cu. in., then divide by 12.5 (the height minus 1.5 in. for material thickness) for 205.4246, divide by 8.5 ( the depth minus 1.5 in. for material thickness) for 24.1676 plus 1.5 ( again for material thickness) for approximately 25.5 in. So a box that is 25.5 in. wide by 14 in. high by 10 in. deep will give you a good airspace for the sub and the type of music you like.
You'll need to adjust according to where you want it to fit but this should give you the general idea on how you would go about figuring out the size and shape you need.

well said "greg s." the type r would be a much better speaker, i would look into a free air speaker, if those still exist, if a single cab truck not much room to build a box, and to get those type E to sound good you have to have a good bit of air space, and usually a good tuned ported box. Type r better but mounting depth is probably alot deeper, because of width of the magnet. Good luck with this in your truck man. probably get as good of sound out of a good mid bass speaker i know kicker makes an 8" that is free air. but a good set of 6 1/2" speakers amped would sound good in that small air space.