CAMS does "targeted scrutiny" for circuit races, and have done for a few years now.
Basically, cars are self-scrutineered for four out of every five events (I think they're the correct numbers), and can be checked at any time. At the 5th event, the car is checked more thoroughly than used to (because the scrutineers have 20% of the workload, that have a lot more time.
It's funny how many competitors got upset by it, but it's working fine. Despite the more thorough checks, apparently fewer defects are found because competitors are taking more responsibility for their machinery.
