Hay buddie, i've just recently got a 7" tft screen from side to side, and it does take a fair while to do it, my mate did my system for me, i'll see if i can get a picture for you, and yeah, you lose a passenger side air vent, and you have to use zip ties to hold the screen mount in place, and then pop the screen in place, i also have a clarion 7" touch screen in my dash as my main head unit.
youi get ots of lookers. i;ve been pulled over by the cops too and they didn't say anything abt it beeing illegel having a screen in the passenger side dash. you must have a passenger if you have the screen on while driving.
i'll get some pics up soon