Worst road rage i had recently was from another cyclist..... He was very serious looking, matching kit, shaved legs, very expensive bike. He pulled in front of me as I waited at some traffic lights... and who was I to be in his way? A weary rucksack laden scruffy oik on his way back from t'mill....
as he sped off in his very serious manner I realised he wasn't as fast as he kit suggested, in fact I could have easily overtaken him, but I was in no rush... as I cycled along in the rough cycle lane and he cycled just outside the rough cycle lane (probably very expensive tyres) I consciously stayed at least 5-6 bike lengths behind, we all know it's rude to draft a stranger, every so often he would look behind with a furious look on his face, see I was there and make a futile attempt to accelerate. This farce carried on for maybe 2 miles. As my right turn approached I pulled out into primary position accelerated up to speed with the traffic and sailed past him, as i got to my turn I waited patiently in the middle of the road to turn right (lots of oncoming traffic) as Mr serious road past I was the victim of a torrent of foul language and hand signals.... I retaliated with the pride obliterating belly laugh that he truly deserved.
With cars I just try to smile and wave. But the occasional bit of bad language escapes if it's an act that makes my adrenaline flow!