Best place for 2 subs in a cargo van

I have two 12's and a van with nothing in it but the front two seats, front door panels and a rubber cargo matt. Where would be the best place for my subs? Way in the back, just behind the front seats....? oh and the 12's are 1200w a peice and the amp is 1200x2@4ohm

Sorry about the vague post. I want it as deep as it can go but still sound clean. The box that they will be in has to be built to fit where they are going to sit. Sealed or vented also is not decided because I dont know whats best for this applacation. Im not looking for a prize winner. Just a slight head turner. I have been thinking of many diffrent spots and how to build the box/boxes to be as out of the way or even useful if possible. I really dont want the van to lose its cargo abilty but if it takes unhooking and moving the box to load stuff up for the best sound, thats fine. So far my ideas are one over each weel well with the drivers side pointed at the passenger seat and vise versa. With that im thinking I might not get as much out of them as I would if they where closer. Another Idea is to put one behind each seat at lower back level. I know I would feel them then but im not sure of the sound. The subs are Directed 12' sx The amp is Directed D1200

Well if I am understanding your idea for placing the subs on opposite sides, then you might run inot a lot of cancelation problems. Their sound would be in a sense "crossing" eachother and causing noise issues. I suggest a box that is built to specs given to you by Directed. You can also look into WINISD for a nice box size ("tutorial" is a sticky in this forum) too. To find the right location you should move the box around till you like it. You have plenty of room to work with so the placement possibilites are limitless.That's my opinion. Take it, leave it, or correct me.

Ideally, place both subs together in the same area, in one of the rear corners of the van. Face them towards the rear of the van or downwards. You need to try spacing them at different distances away from the rear or floor depending on their orientation, to hear the different loading effect it has. If the van is empty, get ready to have a lot of rattles and panels resonating from the bass. Consider applying deadner to everything.sparky