IT'S just about the Holy Grail of saloon cars...the model that has withstood the onslaught of concerted ‘niche' invasion and come out on top.

The 3 Series BMW has been within the sights of other manufacturers for years and survived challenges from SUVs, hatchbacks, crossovers and other saloons, particularly from Merc and Audi.

The posh arm of giant Toyota, Lexus, has also targeted it but until now its IS saloon hasn't managed to hit bullseye.

However, the latest incarnation of the four-door IS could have the credentials to succeed.

A confident blend of extrovert styling, fine engineering alongside competitive pricing give it a good chance.

I chose to try out the IS 300h hybrid version which at £29,495 clocks in at just £4,000 more than the base model, and it's substantially more frugal thanks to state-of-the-art technology that's unavailable in rivals.

Powered by a 2.5-litre petrol, four cylinder petrol engine knocking out 178bhp coupled to an electric motor, the result is a reasonably swift sports saloon that neatly sneaks into the zero tax threshold because of CO2 emissions of just 99g/km.

This translates to real-world economy of near the 50mpg mark. The official combined figure is no less than 65.7mpg, but you'd need a strong tailwind and long downhill slope match that statistic.

As far the driver is concerned, the fact that this is a hybrid has little effect on driving characteristics.

It's extremely quiet, refined and smoother than most six cylinders. The CVT gearbox is slick and comfortably matched to the power system and possesses none of the ‘hunt-and-search' impression of some continuously variable transmissions.

The third generation IS has the most handsome styling so far, in my view, with strong, masculine lines that illustrate the direction of future Lexus designs.

Cabin space is more generous with noticeably better rear legroom and a bit more shoulder room between driver and passenger. Boot space is improved, too, with 450 litres storage.

Acceleration of 0-62mph in 8.3 seconds and a maximum of 125 is a tad down on 3 Series and new C-Class but the extra refinement and ease of driving is reasonable compensation for most.

Even pressing on into three figure speeds noise levels are barely raised. Road holding is neat and tidy and there is a bit more steering feel transmitted than most Japanese models. Cornering roll is well contained but there's sufficient movement in the suspension to allow poor surfaces to be smoothed out.

It isn't quite as athletic as the Beemer over twisty stretches but there can be no doubt about its security or strong grip.

The cabin oozes quality with robust switchgear and easy-to-read dials, although I wasn't won over by the mouse-like control to operate the sat-nav. Doors close with a reassuring ‘thunk' and the build quality feels rock-solid.

No shortage of standard equipment - the SE version has cruise control, dual climate control, rear view camera, tyre pressure monitors and front and rear parking sensors.

Fine looking and beautifully finished, the latest IS offers genuine prestige within a practical and economical package.