CAR manufacturers are never slow to inform us how technically, dynamically and stylistically superior their new models are compared to the offerings from rivals. That's promotion for you.

Apps pop up, screens flash and a synthetic sexy voice tells you the easy way to trawl through layers of sub-menu.

The one thing missing though, especially as we reach the premium end of the new car market, is serenity and relaxation.

It's something Lexus took on board long ago and the Japanese brand's new RZ line-up represents a serious step forward for all-electric luxury SUVs.

Though it shares the same basic underpinnings as Toyota stablemate the bZ4X and Subaru Solterra this first bespoke electric Lexus is larger and more upmarket than the former pair.

While the range starts with the front-wheel drive 350e (now costing from a competitive £44,165), our variant was the higher spec 500e with DIRECT4 all-wheel drive.

With an extra motor as part of the package the RZ 500e produces 402bhp for near lightning acceleration of 0-62mph in 4.4 seconds.

And while it may not convey that power rush you get from some big battery EVs, prodding the Sport mode in the car's drive settings certainly gets you close.

The only issue concerns range - especially given the ongoing concerns over range anxiety and the arrival of ever bigger batteries - which in the case of the 500e with 20-inch wheels is 285 miles.

As for charging speed you can top up from 10 to 80 per cent in 30 minutes using a rapid charger provided the battery has been pre-conditioned, something you can activate via the infotainment set-up.

Refinement though is top notch as the RZ glides effortlessly over broken surfaces and potholes, is silky smooth at speed, has minimal wind noise and zero road noise while handling is competent rather than pin sharp around country lanes.

Inside the cabin the RZ really comes into its own, the car's radiant heating - an infrared system located beneath the steering column and lower front dash - providing those in the front seats with a warm blanket effect.

Instead of heating the air, it directly warms passengers' legs and lower bodies, conserving battery range by reducing the load on the climate control system.

Otherwise there is a 14-inch touchscreen at the centre of the dash with a simple menu layout, comfortable front seats with powered adjustment, an optimum driving position with clear visibility and acres of space.

That airy, open feel extends to the rear too, with more than enough legroom for tall passengers, plenty of headroom as well, plus the bonus of a centre rear passenger being able to travel in comfort thanks to the available width and the flat floor.

Build quality is exceptional with soft-touch materials throughout. Stowage space includes the likes of cup-holders and cubbies, a deep container beneath the centre armrest and a smartphone charging pad ahead of the auto gear selector. You don't, however, get a glovebox.

And to underline the RZ's practicality there's a rectangular 522-litre boot with low lip which extends to 1,451 litres of space with the 60:40 rear seats folded. You also get an extra 58 litres of space specifically for charging cables and small items and a powered tailgate.

Standard kit is extensive anyway but splashing out on Premium Plus trim adds items like ventilated front seats, a panoramic double glass roof, head-up display, 360-degree camera and driver's seat memory function in addition to a full suite of safety features including nine airbags and blind spot monitoring.