I don't understand why other drivers get so arsey about people who have their roof down.
firstly, are bikers exempt from being called all sorts? Secondly, cars have been fitted with heated seats and blowers that direct hot air to your face for longer than I've been alive. Lastly, whats the difference between driving with the roof down and walking?
I think most of it comes down to jealously. They'd like to do the same but can't because they either can't afford to (highly unlikely as you can buy z4's cheaply now) or they didn't have the bollocks to own something a little different/impractical, so went for a bore fest hatchback.