I have a Treg 2004 and I'm looking into replacing the nav system and the HVAC buttons with a computer and a big screen like the tesla one. I have been running a computer on another car but kept the hvac buttons. Do you guys have any info on sniffing and mimicking the hvac buttons? The treg uses the CAN TP 1.6 protocol according to what I've read so far. I will be using Windows and a c# application for the hvac. The nav system/multimedia system is easy to do.  There are even ready made frontends I've been using with my other car. There are Tesla style Android units on the market but nothing for the Touareg