a vehicle would need a front-mounted camera and a radar transmitter with at least an antenna at the rear. When a safety problem is spotted, like an obstruction in the road, the system would begin recording and tag the clip with metadata, like size, distance, and whether or not the object is moving. All of that information would then be broadcast to other cars nearby.
Leave it to Google to find a simple solution using common parts to solve the blindspot problem. Now let’s see who can implement the concept and pay licenses to Google, perhaps they will open source the technology. Google wants to end distracted driving so phones in cars don’t become as illegal as open bottles, I think.