I don't know about Sherman being a mechanic, might have been Dub, he was the better mechanic, or Layman. I think there was another John Utsman.
I am not aware of this, I thought the in-car camera was developed in Australia. Racing Radios, the first to sell/rent fan scanners was in Johnson City.
For some reason I remember someone telling me that the guy who owned our summer league team hit it big by inventing the in-car systems. Could have misunderstood. Can't remember the guy's name for the life of me though.