Here's the instruction/owners manual for the interface
https://pdf.crutchfieldonline.com/Im...541RP5GM11.PDF
Just make sure whatever head unit you select is supported - I believe most are, but it would be good to confirm. I believe the button behavior is also customizable, but I left it with the defaults to match what the factory defaults were. Works great - have used it for about 3000 miles now without even a hiccup.
Thanks
Eric