I have recently installed the Icom IC-440, current model Patrol with the upgraded sound system, thought I was going to get the CD/Radio, and do what you are going to do.
The new double din system is I think too good to take out, I did not want to drill or cut a new vehicle, no where could I find to effect a clean install. With the IC-440, I installed the "box" up under the dash on passenger side, ran the mic cable inside the centre console to the end where the rear passenger ashtray is, and now when I want to use it, take out the mic from bottom of centre console, remove the ashtray and plug it in. The cable come up over the centre console, does not foul the gear levers or get in the way.
When not in use, and stowed, except for the aerial on the b/bar, you would not know there was HF!

I would post a pic, but there is nothing to see
Oh, and guys who have in dash radios, say it sounds better than thiers.....