I just recently got a Orion H2 10.2 sub and a Orion 2500d amp and running a 260 amp alt., 0 awg wire, and big 3, my question is Im building a box for my sub, I drive a 01 cavy, facing the box into the car and sealing the trunk completly off from the inside of the car, my box I was thinking bout going with is 24" Wide x 14" High x 18" Deep with the port 4" wide total port length 33" so 1.72 cubic feet, tuned to 44.9 Hz, now does anyone have any opinions or suggestions on this design?

Use aeroports instead. Daily listening 44hz will sound like poo. You now have more room for you sub since your not having a port take up room and adjustable ports. It may look ugly but I also suggest external ports. And sealing the trunk from the cabin with subs firing into cabin is a very good move. Did that with my old set-up

The design sounds good, but watch your box volume.
Many, many people have had troubles keeping their H2s alive on RMS power in the recommended enclosure volumes that Orion publishes. From what I've gathered, what Orion recommends is too large, and the sub doesn't have enough control when pushed. They seem fine when put in smaller enclosures.
Not sure where 1.7cuft is with respect to Orion's recommendations, but keep that in mind seeing that you're running the 2500d to it..

J.J. Lecznar wrote:... bring ur @!#$ over here and i wil blow what u have to hell.... ill put @!#$in 200 dollars on it...

*wipes tears from eyes*

lol orion recommends in their manual 0,6 cubic feet tuned to 28Hz thats seems right out to lunch lol, and this is NET box volume speaker and port displacement are not calculated into the volume of the enclosure lol