New Tacoma looking for some advice

Hey guys new here and I just bought a 2006 dc prerunner. I spend a lot of time in my truck and I like a good sound system. I've been lurking these posts and am wondering if there are any other options for a sub other than behind the rear seat (I like the storage). I was thinking of replacing the head unit or adding a small powered sub under a seat. I think kenwood makes a slim powered sub. Let me know what you think or what has worked for you. I have a nice 10" sub but it seems as though you have to do some mods to fit it behind the drivers side rear seat. Thanks guys.