Glad to see the 'wink' now a 'nod'.
I'm the same as TC, if I see a copper on a bike then I'll plod-nod and usually get the same in return. I guess the only thing I don't do is mod-nod's at those poor unfortunates on their mobile hairdryers. I must admit I was tempted to nod a biker at a service station one day (out in the car), but refrained in case I made a complete tit (just a partial one at the moment) out of myself
.