I'M often asked what car I would buy, within reason, if money wasn't part of the equation.
Well here it is, the Jaguar XF Diesel S. And for a little extra indulgence, it's in top spec Sport Portfolio trim.
You may wonder why I am picking an oil-burner rather than, say, the 5-0-litre V8 supercharged petrol XFR.
The answer is simple: this is one hell of a diesel engine - quiet, refined and wickedly powerful, yet capable of an official 42mpg average.
There are actually two three-litre V6 diesels available in the XF, a 236bhp unit and the tested 271bhp engine which comes in 'S' versions.
Key to their amazing punch is sequential turbocharging, whereby one turbo operates at low revs while a larger one kicks in at higher revs.
Upshot is that the XF Diesel S can scorch to 60mph in a mere 5.9 seconds and, if you were on a racetrack, could probably get close to its 155mph maximum.
As for ride and handling, well the XF has the stiffest bodyshell in its class so control is precise, the steering is extremely responsive and there are new technologies like computer controlled damping.
In its slower paces through the suburbs it soaks up bumps and cradles the driver and passengers in time-honoured Jaguar fashion. Open up on the faster roads and you witness terrific pace plus a feeling of being glued to the road through fast bends.
That's the dynamics sorted, so what about the styling and comfort? Travelling in the XF is all about sporting luxury and cutting edge yet practical design.
Hop inside this super saloon and you both feel and see the car's heart begin to beat as the start button pulses red.
Press to fire up the engine and the alloy gearshift rises smoothly into the palm of your hand. At the same time the colour touchscreen at the centre of the dash bursts into life and the rotating air vents appear as if by magic from the fascia.
If that's not enough there are proximity sensors on the glovebox and interior lights that activate with a wave of your hand and, for night time, phosphor blue mood lighting that echoes the ambiance of a trendy bar or restaurant.
Even the glovebox features a tiny bullseye sensor, sampled from the Quadrophenia film poster, that reacts at the softest touch.
All that's without taking into account the likes of voice control for everything from sounds and TV to sat-nav, telephone, climate control and memory.
And despite its coupe-like lines there is plenty of room inside, sufficient to carry five adults in comfort with some decent interior stowage and a useful 500 litres of boot space - the most ever featured in a Jaguar car.
Basically this is a car with everything. It really does have the X Factor.
FAST FACTS
Jaguar XF 3.0 D Sport Portfolio
Price: £44,200
Mechanical: 271bhp, 2,993cc, 6cyl diesel engine driving rear wheels via 6-speed automatic gearbox.
Max speed: 155mph
0-62mph: 6.4 seconds
Combined mpg: 42
Insurance group: 18
CO2 emissions: 179g/km
BiK rating: 26%
Warranty: 3yrs/ unlimited mileage