Yeah go the splits in the doors, they are heaps better for sound quality... mount the tweeters high.

I'm unsure if my ute will ever get sound, but if I were to install anything it would be 6 inch splits in the door/kick panel and probably something like a 8 inch sub and another fill in speaker behind each seat an amp for the 4 speakers under one seat and amp for the two subs under the other seat and a cooling fan setup for the amps... yep I think that I have just talked myself into some sound for the ute... lol... of course in my ute it will have to be totally removable with no screw in mounting points as I don't want to touch the original interior... will have to find a funky oldschool looking head deck...