Funny this comes up - I actually got an email at work the other day from Fuelstar that listed the proper methods for testing the device. I reckon its basically impossible perform a test they wont dispute.
They also mention that
"7.Experience has shown that Fuelstar must be involved in the conduct of tests and be able to observe the trialling"
Our company actually did some independant testing, they never actually released the raw data to us pleb engineers but in their wisdom sent it to Fuelstar for interpretation. I tried to dig it up a while ago but all traces of the job seem to have disappeared...