I have a lot of gear grinding. :P
I seem to have many problems with cyclists. Today when I was driving my AE94 sedan I indicated to go into the left lane and started to move into it when a cyclist went flying past, causing me to slam on the brakes and honk the horn. He looked round, right at me, carried on cycling. Then 5 seconds later he turns round stares at me again.
I also hate many 4X4 drivers. I had a big Mitsubishi Pajero tailgating me one time for sticking to the speed limit and he was towing a trailer. I have driven a relative's Land Cruiser Prado with a loaded trailer, and it is a lot harder to stop the thing with a trailer than without a trailer.
People who think they own the roads, or when people cut corners, or even needlessly be on the centre of the road making me slow down.
Quite a few P platers. I am a P plater myself in NSW, and I have seen many P platers, usually in a high-powered modern car show off by speeding off and doing dangerously high speeds, potentially risking everyone else on the road.
I had some guy who was in a modded Nissan Pulsar pull up in the lane next to me at traffic lights, revving his engine like mad and it was like he wanted to race me as he was staring at me. The lights turned green and he sped off really fast, and I saw he had red P plates on. :|