Thank youI converted mine from having the Rear DVD to not when we did the cage.
We changed the headliner out and it was over $800.00 for the prewired headliner if I remember correctly.
There are I think 7 or 8 different headliners depending on accessories. The headliners are prewired for the accessories.
The headliner without the rear dvd does not have the wiring in it. You would have to purchase the correct headliner for the accessory you want to add.