The interface for yours is retarded.
WTF does a speedometer have to do with percentages? If the test stops at 100, why does the gauge go to 140? Why don't you just have a "XX%" label and a progress bar like every other site in the world? Even if you really want to use a dial as a progress bar, "finished" should be at the end of the dial, not somewhere in the middle. And the dial should be labelled "Percent Complete", not "Miles Per Hour". And using the analogy of speedometer and odometer to display the SAME THING is stupid. Odometers do not display the same thing as speedometers.
Same with the instantaneous bandwidth gauge. It should say "Mbps" not "RPM", as the gauge doesn't measure RPM.
If I wanted to give a lesson in crappy non-intuitive user interfaces, I could use yours as an example. You can respond by saying it gives you directions at the beginning, but it automatically starts running the test and the directions dissapear after a few seconds. I hadn't finished reading them when it started running. anyone who loads up this test in the background or looks away from the PC after clicking won't know WTF it's doing.
Never mind that the test is inaccurate (I get 1693k on your test, and 2425k on boradband reports), doesn't include an upload speed meter, and rips off trademarks from Dodge.