So I understand that since I want a new receiver I need to replace the whole system (2 5.25 speakers in front door, tweeters there as well, 2 6x9's in the back, and a new amp and of course a receiver), however I just need some confirmation before I order everything from crutchfield. I also need to know if the navigation will still work. If so great, if not then do I lose all functionality or just some? Is there anyway to retain functionality?

If I'm totally missing the point here then what am I wrong about? If im on the mark do you have any tips, suggestions, comments?

Thanks for the help.

 

You can use an aftermarket headunit (receiver) on a HK system by using an adapter called the HK Enabler.

https://www.hkenabler.co.uk/
http://newministuff.com/hk-enabler-465-p.asp