Swoop,

Nasty situation - I have been there myself, even to the point of being almost run off the road by a stream of traffic overtaking a stationary vehicle on the other side of the road. Each car just followed the one in front, assuming that the way was clear - cutting off my right of way in the process.

Back to the main subject of the post, I have found it useful to appear unstable on occasion to win a bit more space when the cars are getting close. As for scaring them, it is worth the thought, but a suitable occasion has not presented itself. Thumping the roof has attracted the attention of careless drivers on more than one occason...

Cheers,

Ed