Forget about TV if you have the basic RMC setup. To retrofit TV a new screen, control panel, antenna's, wiring harnesses, TV tuner and 5F module is required so your looking at a bill of around £1500-£2000 just on parts (with most being used). You then need to install that lot yourself or pay someone to install it.
Easiest install is a car with tech pack fitted & BOSE so the optic cables are already ran to the boot.
I have TV on my C6 A6 and it does come in useful (waiting for the better half) and you still get audio on the move, and let's face it everything is a repeat these days. I just listen to top gear on the way home from work. Going to retrofit it on my C7 but I only need the module & antenna's, as it was a lot cheaper that the £1000 option from factory.