complete w****r , certain motorists hate the fact that cyclists tend to make faster progress in todays traffic, I remember having a very satisfying race with a guy in his audi into town which was about a 3 mile jaunt,he passed me close at speed revving his engine as if to make a point, I kept catching him at all the lights after doing 30 mph sprints with a tailwind, keeping in the flow of the traffic . He HATED that,I could sense his frustration. I got infront of him and slapped my muscular thighs LOL, thus making a point back..I dont need a powerful engine ,job done.