When a carmaker shuts half a racetrack and fills the other half with cones and warnings of impending doom, to stop you from extending the car to its limits, you know those limits are just too high. For the health and safety people, at least.
But that's exactly what happened at the launch of the 2013 Shelby GT500. Citing the crashing of three Camaro ZL1s at its GM competitor's recent unveiling at the super-quick Virginia International Raceway, Ford decided to limit our track time to a few minutes on a section of the fabulous - and normally very fast - Road Atlanta track.
So there's very little I can tell you about what the car is like at speed. Despite speed being the reason most of us were there... with a maximum speed of 202mph, it was always going to be. There were a couple of pro drivers who gave us hot laps at warp speed, but the only thing to be learned from thatwas that we all just wanted to have more of a go ourselves.
We were later allowed several runs up a drag strip on our own (gasp!), to experience the clever launch control system - you dial in the launch revs, flatten the throttle and release the clutch for a perfect send off - but other than that, all the impressions were gained on narrow, leafy Georgian country lanes.
And, while it's enormous fun to get diagonal out of junctions and leave every traffic light in a haze of blue tyre smoke, after a couple of hours of not being able to really extend the car, it all started to get a bit frustrating. With 662bhp and 631lb ft from its supercharged 5.8-litre V8 - the Ford GT supercar had 550bhp and 500lb ft - maybe the new GT500 has finally reached the blooded edge of the envelope. The ZL1 Camaro is super-fast and has a clever chassis, but this new mutant Mustang beats it in almost every numerical way possible. More power, more torque, higher top speed, faster quarter-mile, higher terminal speed, lighter weight, lower price...
But, in messing with the Mustang's DNA to make it a 200mph+ car, a lot of the wring-its-neck pleasure you'd expect from a muscle car has gone. Try thrashing the GT500 as hard as a regular Mustang, and you'll lose your life or licence. So the net effect is that, for all its ability, it's simply not as much fun to drive as some of the lesser models.
I am bowled over by the achievements of the GT500, but even as a dyed-in-the-wool Mustang fan, I wouldn't recommend buying one. Much better to buy a Boss 302 Laguna Seca and spend the saving on track days. At circuits that haven't been half coned off.
5800cc, 8cyl, RWD, 662bhp, 631lb ft, 19.0mpg, n/a g/km CO2, 0-62 in 3.7secs, 202mph, 1751kg
Extraordinary feat of engineering from Shelby. But - and it pains us to have to write this - not as much fun as Mustangs with half the power.