Not much activity here, but I'll keep trying.
Do you love the Furrion DV3300 as much as I do? Sound quality, intuitive UI, handy remote - it has it all! Despite all its wonderful features, I decided to change to a double din car unit. Basically, it's pretty simple with a few minor gotchas. There's a forum topic and corresponding YouTube video that covers it pretty well:
One of the biggest problems in the 16FD is getting to the wiring area behind the DV3300. Unlike the forum example, there is no easy way to access the wiring from the cabinet. After removing the DV3300, I used a 2x4 and rubber mallet to knock the black trim panel backwards. It is stapled in place, but being gentle, I was able to break it loose. Though most of the staples pulled through the panel (and had to be pulled out of the cabinet with pliers) there was no damage to the black panel that precluded reusing it. If that doesn't work for you, it should be easy to cut a new panel from plywood and paint/stain. But for me, that was one less operation.
Once you have access to the wiring, just follow what the video shows. Each manufacturer's unit is slightly different, but not that much. You will almost certainly need a little circuit to defeat the parking break interlock. I purchased a Pioneer AVH-600EX and this device (which worked great):
Once the wiring is done and you verify operation, the real challenge begins - mounting the unit back in the cabinet!
Pioneer makes a wonderful install kit, that I think works with all of it NEX units. It really is a slick little kit that will mount in most any panel, has a trim ring to clean things up, and allows the unit to be removed easily after installation.
Using the kit's housing as a template, and being very careful, i was able to enlarge the original cutout to the proper size using a utility knife. But now, how the he** do I get it all attached back in the cabinet? There just not much room to work back there with the panel in place. I considered mounting it with decorative screws, but really didn't like that much.
I finally settled on doing just what Jayco did. I used a good quality contact cement on the back of the cabinet opening, and along the front edge of the panel. Then I fed the panel through the opening, lined things up very carefully and glued it in place. That stabilizes everything enough to work through the double din opening (without the mounting kit). Next I used a T50 staple gun and secured the panel with a dozen or so staples- same scheme as Jayco! It was tight, but not bad.
Slide the mounting bracket in the double din opening, connect all the wiring, slide in the head unit, and snap on the trim. Voila - a very clean install.
After about 2 hours of work, I'm happy with the results. Sound is much better, and the UI is a godsend. You'll notice in the pic that I also installed an external USB and Aux adapter, because the Pioneer only has rear inputs.