One more thing for the motorways, is there any particular etiquette for making a 'go ahead' signal? In the US it's usually a single flash of the lights from the passing lane to let trucks know it's safe to pull into the passing lane ahead of you so they can keep their momentum. The overtaken truck will also use a single light flash to let the passer know they're clear and it's safe to move back over. It's generally done between trucks but I've noticed drivers seem to really appreciate it when a car understands their need to keep momentum and will allow them to make their pass first.