my Pioneer is a little deep as well so I custom made some brackets that would use different mounting holes, but even then it still sticks out a tiny tiny bit...and my double din has a couple fitment issues....
My JVC AVX830 was also too deep. I started out by pounding the piss out of the cross support bar behind the radio only to find that no matter how hard I hit and no matter how deep I dented it, it wasn't going to be enough. Finally, right before I took a saw zaw to it and cut it the F out all together, I was smart enough to call someone smarter than me. I gave James (Tech12Volt) a call and after a 20 minute conversation and about 30 minutes of following his direction, my radio fit fine.
I used the factory brackets, but had to modify them to mount further forward on the radios cage thus enabling the radio to sit out a little further. He walked me through the mod to the brackets and explained exactly how to do it. Wish I took pics, but if your looking at the brackets and the side of the radio where the mounts bolt, you'll need to drill the holes out a little so that you can move the brackets to fit into more forward holes. I only used two screws on each side if I remember correctly. It wasn't possible to make the bracket fit with three and still have any structural integrity.
Just to give myself a slight bit more room, I epoxied two 1/8" pieces of plastic to the dash side of the brackets to stand it off that extra 1/8". Now the radio fits perfect, the wires aren't kinked up and there's plenty of room for added accessories should I need it later.