I'm wondering why you would want such a thing anyway? I would think it would be terribly distracting to your play as well as anyone else near you on the course.
I could see taking along your MP3 player or whatever if you want to listen to music while you play (via headphones or earphones), but I'd be concerned about getting hit by a cart or a stray ball if I was tuned in too loud.
I've heard of cooler bags that will fit on a golf cart and look like a mini golf bag to haul your beer along with you, but never a TV/radio/DVD setup. Good luck in finding one!
The time of day I play golf, all that would be on would be soap operas. I can just see it, me telling the guy playing behind "I'll putt in a second - I just have to see if Nicky is dead or if the mysterious guy who shot her just wounded her? Will she be in a coma for a long time and hover between life and death just like she has 12 times before? Will Victor kill the guy who just shot his wife and wind up in jail so he can't go see her and will her back from near-death? Was it one of the leftover mob guys who shot her?"
Don't think that would go over too well in addition to the noise issue. I didn't realize that people play radios on the course - guess no one where I play does. That shouldn't be allowed, IMHO. If I came across someone playing a radio loud enough for me to hear, I'd be tempted to sing along (now that would clear the course in a big hurry).