If you are laying in the bed of the truck will you be able to hear the movie?

No not unless you can open the back window to hear it from your radio or have a portable radio

I use a radio app n my beats (pill)

Big time yes..

Yes, you was a portable radio. Last time we used our truck and had to leave all windows roll down but it wasn't the same.

Monica in right

Monica is right. I'd really recommend a portable radio. I was blasting my vehicles radio beyond what I'd like just to get minimal results. Even with the back door open (SUV) and sitting on the bumper, you will not get anywhere near a good experience.