1995 toyota supra adding alarm

Do any of you guys know if there will be any difference between a Japanese one of these, and a north american one?  I have an alarm to put into one early next week, and would be interested in a heads up.  I'm hoping the only "interesting" part of it is going to be going under the dash on the right hand side.....Think. It's not illegal yet.

They should be identical, except of course right hand drive. They stopped them in the UK about '93 for noise pollution problems, but we were doing imports for some years. The only complication, wiring folding mirrors (timed output from alarm and 2 x relays required). They are possibly the easiest cars in the world to do, everything's where you expect it to be. Does the dash come away by removing the top, then the lower two sections with heater controls above the radio?  If so be very careful plugging them back, also the AC sensor hose, that's about it.