I just replaced the cd changer/cassette deck on our 2005 RX330 with the Sony AVX-AX100 (car play unit). Purchased the deck through Crutchfield. Simple installation and gained tons of functionality. We do not have navigation. I bought the module to retain the steering wheel controls. I installed a backup camera as well. You can easily add a inexpensive headunit and gain hands free calling and bluetooth streaming and usb playback. The nice thing about purchasing through Crutchfield is they pretty much give you the harness and trim kit to do the install. I wish I could install the same head unit in our 2006 LX470, but the climate control integration prevents it.