I have had the same issue , previously I had a RAV4 hybrid and didn't connect bad DAB signal with the dash cam until I got a new cam and it completely messed up the radio. On the Lexus I have tried putting the cam at all 4 corners of the screen and it always kills the signal, interestingly if you turn on the cam without plugging it in to the car 12V the radio is fine , so it is something to do with feedback on the 12V Cable, I have used a fully shielded cable on the cam and it makes no difference. As the CT200 only has one 12V socket right next to the USB ports I was going to try and find a 12V supply somewhere else but have not been able to locate a suitable feed anywhere. Does any one have any experience in loacating a 12V Aux feed on the CT200?