Piers, you have shamed me.

I won't sing in the car any more, because, yes, you're right. It's not safe to drive and sing at the same time. If a tricky corner came up, I might be trying to remember some line and fail to go round it, because I'd be concentrating so hard on the lyrics that I wouldn't be able to tear myself away and release a part of my brain to rotate the starring wheel ;-)

More seriously, I wasn't suggesting learning new songs in the car (with the lyrics taped to the windscreen?) I was talking about honing them for performance - something you can interrupt instantaneously if something dangerous like a mobile-phone-wielding-student should hove across the bows.

Tom