A few times when I cycle commuted daily years ago. Always slow speed, mostly at stop sign intersections. No serious injuries, just bumps, bruises and annoyances.
Hit from behind a couple of times by drivers who claimed they didn't see me. Same with motorcycles -- drivers behind me at stop sign intersections claimed they didn't see me. That's when I quit braking to a full stop when cars were behind me. Drivers seem to expect two-wheeled vehicles to roll through stop signs, so that's what I do now if cars are behind me, but none are approaching from ahead or to the sides.
Ended up across another car's hood when a driver turned into me, even after we'd made eye contact and she seemed to acknowledge that I had right of way to go first -- again, she claimed she didn't see me. The most common excuse.
Doored once by a diplomat's limo in downtown Washington DC. Just a scrape, not a collision. I thought I'd left enough room to avoid dooring, but his limo had unusually long suicide doors. Naturally he yelled at me in some language I didn't understand. Being a lowly enlisted man I figured it could only go poorly for me so I skeedaddled since I wasn't in uniform and didn't have far to go to get off the street.
Nowadays I'm much more cautious and simultaneously assertive but not aggressive. Eyes on stalks, head on a swivel. I take the lane where appropriate, signal very prominently, and expect drivers to ignore me or do something stupid unless I make it very clear what I'm doing. I try to avoid confrontations, never initiate disputes, but I don't back down from idiots who claim bicycles belong on the sidewalk or playground. Invariably those drivers have no valid excuse for trying to bully cyclists -- it's always on lightly traveled roads, where they have plenty of room to pass safely, yet feel entitled to waste my time and theirs with misguided traffic rules they just invented while complaining that cyclists are slowing them down.
On the plus side, the vast majority of drivers I encounter are at least tolerant, many are very courteous and considerate. I try to acknowledge those little courtesies whenever possible.