So it's hard to say what was more impressive when PH met up with touring car racer Paul O'Neill and the all-new Vauxhall Insignia VXR - the fact that the car took all the punishment Paul could throw at it, or that a professional racing driver was mechanically sympathetic to a road car. We'll call it a bit of both so that honour is satisfied for both parties.
We took Vauxhall's latest super-saloon to the famously challenging Alpine course at the Millbrook test facility to see how the Nurburgring-developed Insignia VXR would cope. And we put BTCC driver Paul O'Neill in the driving seat, just to add that extra bit of spice.
So what does he think? "It's a big car, but it just doesn't feel like it as soon as you chuck it into a bend," says Paul. "It's refined, comfortable and usable on the road - a real everyday car - yet once you get it on the Alpine course it feels like a proper sports car."
With 321bhp and 321lb ft on tap from its 2.8-litre turbocharged V6, the Insignia VXR certainly has the performance to match a 'proper' sports car; 60mph will arrive from a standstill in 5.6sec and the top speed is electronically limited to 155mph. Still, there's no pleasing a racing driver. "You know, I do wish it had a tiny bit more power" says Paul with a wink, before remembering his 'corporate responsibilities' and adding "only because the chassis would be so obviously up to it, of course." Yeah, right Paul...
The cleverest trick of all, however, is the Insignia VXR's 'HiPerStrut' front suspension. This is an evolution of the regular MacPherson strut set-up used on ordinary Insignias and allows the front tyres to maintain a greater contact patch during cornering, improving grip levels and reducing understeer. We don't know this at the time - I only find that out later. Paul spots that there's something clever in the suspension straight away, though. "I don't know what they've done with this suspension, but it's trick stuff; well damped yet with a dead-firm rebound."
All that clever chassis technology is clearly confidence-inspiring, as Paul immediately attacks the twisty, tricky Millbrook hill route with gusto (having first switched to 'VXR' mode, of course). Despite the squeals of protest from the tyres, the VXR hangs on at improbably high speeds, all the while feeling totally secure.
The Insignia VXR feels exceedingly well damped, too; that trick front suspension clearly does its job well. There's one particular section of the hill route that's especially unnerving for passengers - a downhill straight followed by an off-camber right-hand bend that goes into a crest.
Despite its size, the VXR copes admirably. We head into the downhill braking zone and Paul gets hard on the four-pot Brembo brakes very late. I'm almost convinced that the negative camber of the turn is going to pitch us off the track but, with a squeal of tyres, the Insignia is through and accelerating towards the crest. Which we jump, taking to the air by what must be a clear 12 inches. I brace myself for a splitter-crunching, bump stop-testing impact as we land, but it never comes. Instead the Insignia touches down deftly and gently - almost as if it had never left the ground. Paul turns to me. "Now that is proper," he says with a grin.
"The ESP is really unobtrusive," says Paul. "It lets you adjust the car's attitude in the corner quite a lot - but it's nice to know it's there to catch you. The only bit where it really intervenes around here is that bit where the crest just on the apex of a right-hand bend throws the right-rear wheel into the air. That sends the car sideways, but the ESP catches it before it gets too far out of line - which is a good thing, because we're travelling pretty quickly there."
After almost two hours of fairly continuous running, our time at Milbrook is up, and the Insignia VXR (and Paul) can take a well-earned rest, although the only tangible signs of the Insignia's thorough workout are some warm-smelling brakes and a very hot engine bay. For what is essentially a large family car - albeit a sporty one - to shrug off such punishment so easily is mightily impressive.