THE Lexus RX was always a car that was ahead of the game, kick-starting the luxury SUV sector when it hit the road 20 years ago and then becoming the first premium motor to feature hybrid technology in 2005.

More recently, though, it slipped behind rivals such as the Audi Q7, BMW X5, Land Rover Discovery and Volvo XC90 because of one major omission - there was no seven-seat version.

The Japanese car-maker has finally plugged this glaring gap in its range with the arrival of the RX 450h L - stretching the five-seat RX by 11 centimetres to make space for two extra backsides.

The additional real-estate necessitates a flatter roofline and less steeply raked rear windscreen, to help to accommodate passengers in the third row, but otherwise the styling is much the same as its smaller sibling.

The nose is dominated by the brand's bold ‘spindle' grille while the lines are sharp and angular - creating an imposing presence on the road.

The two additional seats are upholstered in the same leather as the rest of the high-quality cabin and have their own cup holders and air conditioning controls. Powered operation also allows them to be individually raised or stowed simply and easily at the push of a button located in the boot.

As with most seven-seaters, though, it's best to regard the extra accommodation as being for occasional use only - and then probably just for the kids. The contortions required to get in and out and limited headroom will make the extra seats unsuitable for most adults.

It's also worth noting that to allow for any leg room for those at the back the middle row seats have to be moved forward, impacting on the knee room of passengers there.

That said, if you're mainly ferrying kids around, the larger Lexus is certainly worth a look as it offers decent family practicality, a very plush interior and three well-equipped trim levels - SE, Luxury and Premier.

Even with all seven seats occupied the boot will take a few shopping bags and boasts a 495-litre capacity in five-seat configuration, rising to 966 litres with the 40/20/40 split middle seats folded flat. There's also plenty of storage around the cabin for personal items and USB sockets front and rear.

All cars get alloy wheels; navigation; electrically adjustable, heated and ventilated front seats; triple-zone air conditioning; keyless entry and ignition; a reversing camera; powered tailgate; and an eight-inch infotainment screen with touchpad interface.

Stepping up to mid-range Luxury trim adds upgraded navigation, a larger 12.3 inch display, DVD player and a wireless smartphone charger.

A comprehensive package of safety features includes automatic emergency braking, adaptive cruise control and lane departure warning.

There's only one powertrain available, combining a 3.5-litre V6 petrol engine with electric motors mounted on both front and rear axles and mated with a constant variable transmission.

It's a meaty combination which will shift the considerable bulk of the RX 450h L from 0-62mph in eight seconds and on to a top speed of 112mph, as well as offering intelligent all-wheel drive.

Around town the system will operate silently and cleanly in electric-only mode for short distances but on the open road you'll be relying on conventional propulsion.

For a car of its size, it handles well and feels balanced and stable through corners, although there is some inevitable body roll, and it is an easy motor to drive, without being overly engaging.