I love the Apple CarPlay on my new eGolf for driving, it's actually an Apple Software that remove most of the touch screen and use mostly speech and text recognition. The only 1 feature that I think it worth the hype is the iMessage using Siri, but we can just do it without the Apple CarPlay if we have the Screen Mirroring.
To get this working, all we need is the $20 screen mirroring device + $9 HDMI to RCA converter + Analog TV Tuner which is a must have for all MMI 2G. Yes, for older model like (2004-2006) you need head unit to have FBAS which I have a few parts left for 2-3 retrofits. It's quite simple and painless if you know what you're doing.
There is an app for iOS mimicking the original Apple CarPlay called CarPlay iOS which install the app with the gui like the Apple CarPlay, but it doesn't work due to Apple proprietary data. I thought I would have the Apple CarPlay on my A8L, but no dice... The screen mirroring is much better and work the same without the limitation and the gui.