in the process of installing the subs in my ranger, i had to remove the rear 6x8's to fit the box back there. If you think about it, the rear 6x8's aren't even that useful.....the seat being pressed up against them will muffle them and make them sound like crap. If I were you, I'd scrap them and just install a nice mid-bass woofer in each door panel (i'm using 5.5" mb quart). Here's the fun tricky part......measure about 8-10" up on the crossmember that devides the windshield from the door frame, and cut a hole in that plastic that will accomodate your tweeter. Problem solved! You almost always want your tweeters in the most foreward location to create the effect that the highs are coming from the front and the lows from the rear. If you are handy with interrior work, this process will take about a half hour, but if you've never attempted anything of this sort, I'd talk someone else into doing it cheap //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
PS - I'd buy an amp to put on those tweeters too.......i have a very small Audio Art 70.2 (35w RMS x 2 @ 4 ohm) amplifier that I need to sell ASAP. It's one of the best mid/high amps I've ever owned. If you or anyone else is interested, email me!