I agree for the wind tunnel, I mentioned that in my third post on this thread

it's impossible to quantify the effects of wingtips on total drag with our conventional RC equipement


for the radar speed mesurment I don't agree. not reliable enough. you should make your pass at exactly the same weight (fuel consumption), exactly same altitude and azimuth (paralax error) and exactly the same RPM to be able to prove something.
I forgot also to mention that the wind would also be the same