Well from the look of it, i believe it replaces the whole factory headunit surround piece (which iv anyone gets this, ill happily purchase off them :D). For the professional wiring ask Toyota and stuff about it, cos they would be the best place to go, I went to my Toyota dealer with all my enquiries and they usually tell me wat i need to know. But for that price you can get the Pioneer Nav Xtra for the same price which is a full blown Entertainment unit. But if someone ends up purchasing one of these, I'll congratuate ya and hope it turns out good AUR15