I've been considering using that JL XR 3 way component set (forget the model number). Perhaps make a plate to hold the mid in the stock door speaker location, tweeter in the stock place, and the 6.5 woofer in the rear speaker place. Another possibility is to get some kickpanels made for the mid and tweet and put the 6.5 in the door location.

I'd probably use the JL 300/2 amplifier for them.

The system would look something like:

JL 10w6v2 sub in a custom fiberglass enclosure similar to the ones in Zland's or Onecoolee's cars (in the left rear corner of the hatch). I wanted to use a 10w7 but I can't justify giving up that much space and money and running the 600-700 watts it would need. I'm figuring on getting the one like Zland's because I am finding it increasingly less desirable to dick around with fiberglassing and San Diego is only like 2 hours away. Anyway, the rest would be:

JL 500/1 sub amp
JL 300/2 amp for 3 ways
JL XR 3 way component set

I am undecided on the headunit. I sorta like the Pioneer 9400MP for the adjustability on it--time correction, 13 band eq--but some of the Alpines are decent as well, although I do not like how they look.

If the 3ways are a bad idea, then the I would swap out the full range amp and components to:

JL 300/4 amp
JL XR 2 way components for front and
JL VR coax in the back.
Sub amp and speaker the same.

Which would be better?

 

I just got the JL XR 3 ways installed except that I had them installed with the midrange and midbass next to each other about, the midrange is 45 degrees left of the stock 6.5 location.
Fromwhat I can tell there is some cancellation because 3 ways are meant to be sepearated. I definitely would not put the 6.5s in the rear because they are midbas and you will lack that in the front stage. I would definitely build kickpanels for them for the best imaging.