I have one of those new home ATSC digital tv tuners and an amplified antenna in my car running off of an inverter feeding a signal into my head unit via RCA video inputs.
Problem is, the tuner only gets a useable signal when the car isn't in motion.
Any speed over 5km/h causes it to pixelize and drop out, until the car is stopped again.
Anyone able to get a useable signal while moving?

 

I guess I will answer my own question for those of you interested....

The ATSC digital broadcast standard was never designed to be received by a mobile device, or anything else that moves.

Another standard will be created for mobile devices in the coming years.