Hehe, love the piccie!

Looks like the engineers that designed the dash never though anyone would ever want to mount a pullout in there, and really crammed everything in right next to the HU... You'd have the very same problem with any other pull-out unit or any unit that didn't have the side mounting holes and instead relied on a sleeve.

Regarding your wiring issues, you might want to give the Toyota Talk board a try,
found this post there. And/or the alt.autos.toyota usenet news group.

/Michael