dual 12 sub enclosure

I don’t know if I am posting this right. Haven’t ever posted to a forum before. I have 2 Alpine Type R 12’s. They are ran off a Planet Audio PL4000.1D amp at 2 ohms. I need a new box as I think the one I have is inadequate. Any ideas or suggestions? It is in the trunk of a 1996 Dodge Intrepid. I...