My Son-in-law put one of these in my 2004 RX300 (He's a wizz with this stuff) There was no instructions with it so you do need to know what you're doing. I have everything functioning. Steering wheel controls etc. heating / air con controls, There's satnav, radio, Attached USB ports, you can save music to the memory, Torque (IE, Full system monitoring, fault codes, fuel trims, etc) I have the software for the LPG system (Which my S-i-L installed, then we got it inspected & certified) Reverse camera, probably more which I've forgotten.
A lot of reflection, sorry about the quality of the photos, .