I'm with the OP on this. On the OG EVO you could go into dev options and set it to keep screen on while charging/plugged into USB (regardless of application). Like the OP I like to have the screen on in the car (while plugged into my SUV). The a/c vent is right behind the phone so it wouldn't over heat. When playing the Samsung Music App, I too would like to have the screen on (even dimmed) so I can change either Pandora Stations or songs in the native app. I haven't found a solution within any of the options and just might do the "screen on 10 minutes" approach when in the car, perhaps using tech tiles or something. I hope there is a less "out of the box" solution for something so easy and available on a much older phone (HTC EVO).