I have installed this unit but and still waiting for the adapter cable to connect the Navibox-1 interface cable to the TID-735NRBT head unit. Seems as though it is an "optionl" part and not included with either the Navibox-1 or the head unit. I'm still wondering why the provide the interface cable that won't connect directly to the head unit or at least include the adapter with the nav unit. Farenheit/Epsilon Customer service is terrible! It took me about 8 calls to finally get to tech support and then another 5 or 6 the get to parts. At least the adapter was a no charge item. Map up date are Navteq and it appears as though they need to be purchased through Farenheit parts department. I'm still researching the availability through Navteq directly. I would rate the box higher but because of the cable issue I am lowering my rating. I'll re post once I have it functional. Mechanical installation was easy, but mount it someplace you can get to the SD memory card.