I've only skimmed through this thread so might have missed something, but as the OP says the man was messing about with music - he wasn't making a phone call. That said, my phone is 'plumbed' into my car so answering a call is a matter of pressing a button on the steering wheel, but for cars without that technology, hands free equipment is available so why on earth don't people sort it out?!!
Someone mentioned 'Community Speedwatch' in villages. That scheme is in operation in most of the villages in my area, but a friend received a worrying letter from the police telling her she'd been caught speeding in a particular area - she'd been nowhere near that village on that day. The 'Speedwatchers' had made a mistake when noting down the number.