Originally Posted by lexusaudio

installing a lexus factory nav is no more difficult then installing aftermarket. they both require connections to speed sensor and reverse wires for back up cameras. the non nav lexus is not prewired for navigation. lexus wants you to buy a new lexus not upgrade your current one so they dont prewire or encourage adding the latest technology to an older lexus. in fact the dealer will say its not possible to add factory navigation to a non nav lexus but every lexus model has had facxtory navogation added . the factory navigation always looks better than aftermarket installs because the faceplate was made for each lexus install. aftermarket navs require adapter faceplates and they rarely look factory .also most future used lexus buyers never heard of eclipse brand and other aftermarket brands would shy away from buying one with an aftermarket navigation headunit. ............................................. it can be done. the is250 300 factory nav upgrade is actually easier than most lexus upgrades because it does not incoporate the ac heater controls to the nav touchscreen control. the es300 330 also is easy install because oit does not incorporate ac heater controls either. the other lexus models GS, LX, RX, GS, LX AND SC have the ac heater controls switched over to the touchscreen control so extra connections have to be made but all those installs are also possible . having all the ac controls and all the milage data that the factory install provides is worth the extra instaltion problems on those models. but the is300 and the es300 330 instaltions are actuall easier than aftermarket because no adptation to the dash have to be made. the eclipse and pioneer double din are both short width wise of fitting into the factory navigtion trim bezel