Ok I am not a sound buff and am very inexperienced when it comes to what is going on in my trunk. Just would like to get the best sound possible. I currently have a huge ported box that takes up pretty much the whole truck. Do to the size and the fact that it is ported we have it facing the car and I leave the seats down in the back so that all the sound goes directly in the car. Is the best for my car? any any advice is welcome

 

You could find the specs for you speakers that tell you how much airspace you need and go to a smaller sealed box. Or you can turn the box around, just make sure you dynamat the hell out of your trunk.

 

Best sound is facing away from the driver with the seats down. Dynamat your trunk for better bass reflex (and to get rid of the nasty rattles). The trunk will act as a bigger ported box that way

 

Hondakillinglan is right, you would probably be better off finding the specs and building a small sealed box instead. Ported boxes are best applied in hatchbacks and suvs, where the vehicle itself can not offer another chamber.

THe only advantage of a ported box is it takes less of the amp power since the sub doesn't have to push against the vacuum created in the box. Ported boxes, however, have a little more rumble but sloppier bass, (which some like) A sealed box will have tighter harder hitting bass, it will just require a little more amp power. I would go with a sealed box in your truck.
Since space is limited, you could custom build your own box using 5/8" or 3/4" MDF and liquid nail and caulk. When placing it, just make sure the cone of the sub is pointed away from you. By firing it towards some part of the truck (seat, floor, rear of cab) the bass will still resonate (of course you need to dynamat) but it will get rid of that annoying cone noise that many truck systems have. If space is real limited, you could build a downfiring system under the seats if possible, that is how the QLogic systems work in trucks often. The sub is mounted in an enclosure that faces the sub less than 2" from the floor. THe bass resonates out beautifully.
OZRallyats

 

here a pic of how it is looking

 

How is it sounding so far?

 

not bad but i have to leave the seats down....you can see that it is pretty much flush to the seats so it uses the inside of the car instead of the trunk to bounce off....

 

Sorry, for some reason I thought you were putting this in a truck! I would still build a smaller sealed box and face the subs backward, the bass will be cleaner and you will get rid of a lot of cone noise.

 

One more thing. If you decide to build a new box, you might want to angle the back of the box to the angle on the rear seat instead of bding straight up and down. This saves a lot of room and if you do the math you will notice it makes up for a lot of box volume. Building the boc is a little trickier but can be done by anyone. The amps then can be mounted along the trunk opening on an amp rack (or create a false floor with the remaining space and set the amp in flush with the floor, if you have only one amp, you might be able to just dip it into the spare tire well), this looks nice and the pounding subs actually ventilate the surface of your amps. I wish I had a picture to show you of my old setup but I can't find one.