im pretty sure if you opt for the factory sat nav they change the dash panel to accomodate a double DIN setup and they used to use Eurovox all in one units.. they were pretty good when they worked and before Eurovox went bankrupt..

They had tv, dvd, sat nav - but werent touch screen.. now they use the Eclipse AVN6000.. and they arent cheap.. bloody fantastic though..

personally i dont think they are worth $3500 alone for the unit (wish i never bought mine now coz i dont even have the ralliart anymore) unless you were a taxi driver or something where it woul get a fair old work-out.. more just a novelty then anything else, portable ones do the same thing..