Several years ago, I was approaching a left I had to make, less than 30 yards from it, so I was near the centerline, ready to turn; a car sped past me very closely, then cut off my turn by making the left literally 2 feet in front of me.
As a result of that, I stopped 'centerlining', and chose the left-tire-track for my left-turn positioning at that turn. Last year, a CO-WORKER (who rides bikes with her husband) sped around me to cut off my left turn! (She didn't meet my eye at work for six months, but never apologized; she knew I saw her, knew I was outraged by it, because she locked eyes with me right after the fact.)
BUT, I will say, that was the last time anyone passed me there. I've gotten a bit more aggressive about claiming my space.
The really crappy thing is, it's the turn-in to the parking lot at my job.
(A recent LOL moment, though: lst week, I was in line to make that turn, rolling probably 12mph or so, with traffic; the car in front of me started to turn, and I already had enough momentum that I could COAST UP that small incline, and ended up at the top of it RIGHT ALONGSIDE THAT DRIVER! He about shat!)