Not sure how much help this will be, but here it goes....
I installed the front roof liner and did a different head unit and speakers than what can am offered from the factory. I believe it was a Jensen unit that you could get from can am. I can’t speak to how that unit and speakers will install on the factory roof liner, but that part should be pretty straight forward. I did a template for the head unit and speakers and dremeled the holes out.
I didn’t run into any issues when I did a dry run install of the roof liner before I installed the audio equipment. Bracket on the Upper left, right and center and it went in perfect. Are you having any issues with the roof liner itself?
I ran my power cable down the Inside of the drivers side part of the roll cage. There is a small hole from the factory on the inside of the cage right around where it makes the turn to the flat roof part. I drilled this hole out a little wider than it was from the factory. Next, I tilted up the hood and removed the 2 plastic rivets on the drivers side hood plastic. This allowed me to slightly bend the plastic up enough to get to the bottom of the roll cage. If I remember correct, there are 2 large bolts at the roll cage where it connects to the frame? I took a 3’ piece of bailing wire and fished it up a hole in the cage close to where these bolts were. Fished the wire all the way up, pulled it out the hole I drilled earlier with some needle nose pliers and attached the power cable and pulled it back down.
sorry to be a little long winded. It took some time to figure out where these holes are from the factory. Once I found them, it wasn’t too hard to complete. I was trying to make the install as clean as possible and not run any exposed wires outside the cage. If you have any other questions, let me know. Hope this helps!