2005 S2000. Had after market Alpine radio installed. After 10 months, radio would turn off and on randomly. Returned radio, installed second, a Sony, same thing. Got 3rd, same thing. Went to electrical specialist, got new battery, altenator, rewired radio same result. Can anyone give me some insight into this?

 

Sounds like a bad ground connection. Maybe, one to the car --- and not to the radio.