HELP! Problem with radio install

Wondering if anyone can help... tried looking in the forum, found the tutorial (nice write up) but nothing seems to be helping me...

First off, I have a '05 Access cab Prerunner 4cyl, SR5, standard radio, no stg controls. I'm trying to install a previously bought Clarion DUZ385SAT double din radio with the Crutchfield Metra adapter.

One big question, one little one:
Little - there's an extra radio plug that only had 3 wires on it. Looking on the forum, this could be the stg wheel control wire, but my truck doesn't have that option. Is it pre-wired for it?

Big - The mounting brackets that are on the truck fit perfectly to the chassis of the Clarion. However, when I put the sleeve around the unit and then try to put the new faceplate on, it won't fit!!! I have about a quarter inch gap at the top when the bottoms clipped in. I also noticed the black surround doesn't meet the dash by the same amount, which would seem to indicate that the radio is too far forward. However, the Toyota bracets don't mount up to anything else on the radio... Any advice?!?

 

1. Yes, typically Toyota runs the wires for all options in every truck. It is cheaper to make one size fits all harness and bundle it all together.

2. It may not fit in there perfectly. You might also try it without the sleeve. I am trying to picture if it will slide out without it install. I don't think it will, I am pretty sure when you attach the brackets to the HU, they also attach to the dash framing. So the HU should be secure that way.