A couple of months ago, we reported that Lexus was in the midst of developing a three-row version of the hitherto five-seater RX, set to be unveiled at the 2017 Tokyo Motor Show in October. Now, our spy photographers have proved its existence with images of the development prototype you see here.

The mule sports a number of sheetmetal changes to accommodate the extra row of seats, and they’re exactly what you’d expect – a longer rear overhang and a more upright rear windscreen. With the standard RX being compact and low-slung, these changes are certainly necessary to make room for a pair of seats capable of fitting actual humans.

Even so, a rendering produced by Japanese publication Mag-X showed that the seats would likely still be only ideal for small children, or for short journeys. One benefit of the larger dimensions is that with the third row folded, boot space should be significantly larger than the five-seater’s 521 litres.

Seven-seat Lexus RX (above), five-seat model (below)

Despite being covered in full body camouflage, the people-carrying RX should otherwise carry few other changes compared to the regular one, with the shape of the headlights, front grille and front fog light surrounds all appearing identical, as does the side surfacing. The standard car’s 2,790 mm wheelbase is also expected to be retained.

Expect the three-row RX to come with the usual engines, including a 235 hp/350 hp 2.0 litre turbocharged engine and a 295 hp/370 Nm 3.5 litre naturally-aspirated V6 mated to an eight-speed automatic transmission. Also likely to be offered is an RX 450h hybrid with an Atkinson-cycle version of the V6 paired to an electric motor, producing a total system output of 308 hp.

A seven-seat RX would be an important addition to the Lexus lineup, being the brand’s first car-based three-row SUV. Until now, the only way you could cram more than five people in a car carrying the L badge is by buying the Toyota Land Cruiser Prado-based GX or the massive LX, built on the bones of the full-size Land Cruiser. Both cars are ladder-on-frame and lack the road manners of the RX.


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