Unfortunately a lot of drivers just DON'T look properly when entering a roundabout.
Here's the side of my car after an incident involving a cyclist's (helmet-protected) head going straight into my back wing (despite what it looks like, it wasn't me pulling out!)
I was waiting at a roundabout. I SHOULD have gone as the car to my right SHOULD have waited, as opposite me a cyclist was coming onto the roundabout, at a speed where clearly he was not going to turn right, but go straight ahead, the car to my right SHOULD wait, making it clear for me to proceed also.
Those alarm bells where something just isn't right were sounding in my head and I hung back...good job I did. Car pulls straight out, bike just manages to avoid going over the bonnet, instead strikes the front bumper which sends him careering over to my side of the road and into my back wing. If I'd gone, I reckon cyclist would have been the filling in a sandwich.
The angle pretty much deflected a lot of the impact, cyclist and bike were fine bar a few scrapes.
The REALLY annoying thing is that bike had some scratches and neede new bar tape etc. My car got a dent that pulled out but was always creased on the line above the stripe. Mr Magoo's car that caused the whole thing however, had nothing bar perhaps a tiny scratch on the corner of the bumper.