We saw the aftermath of this on our ride on Saturday...
http://www.getsurrey.co.uk/news/surrey-news/shepperton-crash-leaves-cyclist-serious-12728232
It doesn't say in the article but we saw a Cervelo TT bike on the ground and a smashed rear window so suspect the guy was on the aero bars, couldn't slow down in time and went face first into the back of the car!
Spotted Police tweet about this. Do see a lot of people in the aero bars on the rough section on Renfree before (hate that surface!) so not too surprised some carry it on through this built up area. Often a lot of slow downs due to the restaurant and junctions.