I have not seen one on the street either, but I spend most of my time at home.
As for this site, it is far and away more informative than the other site with the "the" in the URL. It is a sad fact that in the US people do not want informative sites. They want misinformation and disinformation. They want to believe that they gained 30 hp from an exhaust, 20 hp from an intake, and that their car handles great even though it is riding the bump stops.
I tune Evos for a hobby, and despite my best efforts to explain to people that GAINS on a dyno sheet are more important than the number that the dyno spits out, the first thing that my customers ask me is "how much power will my car make?" My response is: "Your car will probably GAIN 20-30 hp from a tune."
Then you have the sad spectacle of comparing dyno charts from different dynos (Mustang, Dynojet, Dynomite, Dynapack) that the posters on other sites engage in. It is all so frustrating that I have given up trying to explain it.
Kudos to Mike for creating this site to provide technical information and meaningful power gains from the tested products.