While I'll admit that the indicators on some modern cars are hard to make out and are positioned in the strangest places, they are there, it is the operator that is at fault. Roundabouts are my pet peeve as well, it is a mandatory part of obtaining your licence to know how to indicate when entering and leaving, but I would estimate 90% forget all that the moment they have the little piece of plastic in their hands.
In the large town near to where I live there is a section of road with a roundabout at each end and the main police station in the middle, you might guess who are some of the worst offenders. I once mentioned this to a Traffic Sergeant down the pub and he just laughed. He said trying to get anyone interested in enforcing that particular law would be like pushing the proverbial uphill backwards with a fork. Why then have the law?