Animosity between motorists and cyclists is just a natural part of cycling and driving. Motorists hate cyclists for getting in the way and holding them up for 5 secs and cyclists hate motorists because of the whole SMIDSY thing.
I had my first sufferance of road rage recently. I'm not a 100% innocent party, more like 95%: I cycled up the outside of a line of traffic at a roundabout to get to the front (strictly speaking probably shouldn't do that, but it's not that bad) and then since I was in front it forced the car that was in front to follow me out into the roundabout and so at that point in time I had probably added about an extra 5 secs to his journey time. I can only think something snapped in this guy's head (perhaps motorists don't mind cyclists as long as they act subserviently) and he beeped me all the way round the roundabout and so I, in turn, flipped him my fingers behind me back - again not that innocent but not that bad). This just made him worse, so when we exited the roundabout he overtook straight away, but then pulled and braked in front of me to slow me down. I just merrily pulled out and overtook him - I'm not sure what he was trying to accomplish (he could have done that all the way home and it would have negligible impact on my journey time), I think perhaps he wanted me to stop so he could get out of his car and "talk" to me, as when he overtook me again he wound down his window and was shouting at me, but because of the distance between us and the noise of the traffic I couldn't hear him. Anyway, this continued up the dual carriageway, him pulling in front, me going round - at one point I went off the road onto a path and he pulled off the road across my path into the entrance of a petrol station. I just cycled round the back of his car, carried on a bit, and got back on the road. When he caught up (knob), he shouted something else at me and I said as loud as I could that I couldn't hear him. And at that point I think he gave up, and realised he'd wasted far more of his time than the 5 secs I'd caused him at the roundabout, and drove off. Twat.