How to be a white van gentleman

Debrett's, which likes to think of itself as the authority on all etiquette matters, has published a guide to polite motoring in modern-day Britain . It offers advice on topics such as chivalry, forecourt manners and passenger etiquette. This includes tips such as keeping conversation light in order to avoid in-car arguments and choosing music that meets passengers' approval. Examples of acceptable behaviour include men never making cliched jokes about female drivers and women avoiding spraying perfume inside the car. What would you like to see enshrined in a highway etiquette code? Which behaviours annoy you most in modern motorists?