This, of course, has nothing to do with the conversion process, which has clearly (and inevitably) compromised the car’s rigidity, as shown by the slight but detectable shimmies that can eddy through the car’s structure if you drop a wheel into a pothole or just drive down a poorly surfaced B-road at speed.
The gain comes from the modifications to the rear suspension and have improved both the ride and handling of the 500C. It feels more compliant, less likely to trip over ridges and be deflected by mid-corner bumps, yet no less sharp when you turn into corners and a good deal more fluid through them.
Even so, you’d need to live on a freshly frozen lake before you’d call the ride smooth. Annoying jiggles of a kind you’d never find in, say, a Fiesta pepper your progress and fuel the suggestion that Fiat spent rather more time on how the car looks than how it drives.
The test car came with optional ESP which postponed its activation until it was really needed but even if you switched it off there is nothing remotely tricky about the way the 500C handles at speed.