With all due respect, you are wrong. If you are camping and sleeping in your truck, exiting through a roof panel is about as dumb as it gets. I'm 6' 250lbs, no way I'm crawling over seats in the front to get out a front door.
You can use an adhesive accelerator prep first, or rubbing alcohol, but careful it doesn't haze out the soft plastic. I personally prepped with 85% ACL and used just a little bit of 1" velcro.
That's going to be difficult. The truck wont pair with an external speaker. So you'd need an audio feed from the kick speakers, sent to a bluetooth TX, which will need power. And you'll need a good one, because you can’t have any latency.