Heh heh. Autocar in the UK did a full road test of a Prius including performance testing. Over about 1000 miles. The overall consumption for their test was 22 mpg. They also have a touring route of approx 30 miles they put all their test cars through - designed to simulate 'normal' motoring rather than the official combined figure. They made sure it started and ended with the batteries in the same state of charge. It did near enough the same 42 mpg as a BMW 330D that would leave it for dead...
No comment from Toyota about this example being faulty and asking for a re-test. The car was supplied by them.
Of course all Prius owners claim 65 mpg. Go figure.