Kenwood DNX9980HD vs Nuvi 2595LM map data

[SamSpade13]

I have a Kenwood DNX9980HD installed in my car. I also purchased a Garmin "North America Lifetime Map Update" card for it and tried to register it but it seems that the Garmin-Gods-That-Be won't allow using "lifetime map updates" with the Kenwood unit.

So now I'm stuck with a useless card and still have outdated maps.

But, I also own a Nuvi 2595LM portable device that comes with it's own "North America Lifetime Maps", so...

I understand how to take the main IMG file from the Nuvi, unlock it, and rename it to GMAPSUPP.IMG and put it on a SD card for the Kenwood unit. I'm pretty sure I can also use the same ASR files from the Nuvi unit as well? But since the Nuvi has split-screen junction views vs. a full-screen/switchover view on the Kenwood I'm confused on where/how I can obtain the correct high-res JCV files for the Kenwood?

Also, are there other files that the Kenwood DNX9980HD unit needs that aren't available on the Nuvi 2595LM?

Lastly, does there exist a Garmin model ???? that I could buy off of eBay; use my "lifetime map updates" card on it; and have it get the high-res JCV / ASR and other matching files that would work as-is on my Kenwood?

If anyone has any experience with my situation and would be willing to 'help a brother out' I'd be very appreciative!

TIA!