Look for a ceiling speaker solution 6.5” 4ohm ; you only have 4” to play with for mounting depth. A stock cutout of 6 1/8 ; The stock furrion head unit is low power.
I upgraded to a Jensen Unit when that one died
Original speakers:
https://furrion.com/products/6-5-flush-mount-speaker-white
I used Pyle flush mount low profile 6.5” speakers for the outside; would probably go with a comparable solution for the ceiling.
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