Talk of a Lexus crossover SUV with third-row seats dates back quite a few years. Lexus even rolled out a concept previewing such a model as early as the 2003 New York International Auto Show, the HPX.

Lexus put off a production version, though, deeming the segment too mainstream for a luxury player. Instead, it offered its rugged GX and LX body-on-frame SUV to buyers seeking a third row.

However, the allure of crossover sales is simply too strong to ignore as Lexus will unveil the new RX L 3-row, 7-seat crossover at this month’s 2017 Los Angeles Auto Show.

Lexus has been developing the vehicle for some time. Modifying the fourth-generation RX to fit a third row should have been straight forward given the vehicle’s corporate cousin, the Toyota Highlander, already has three rows.

Lexus RX with third-row seats spy shots - Image via S. Baldauf/SB-Medien

Lexus RX with third-row seats spy shots - Image via S. Baldauf/SB-Medien

However, fitting the third row while maintaining the dramatic rear styling of the latest RX is thought to have presented some hurdles. To provide sufficient headroom for third-row occupants, the roof has been made flatter towards the rear instead of sloping down like on the standard 2-row model.

In the United States, the vehicle will be offered in RX 350 L and RX 450h L guises, though perhaps not both at launch. Potential rivals will be the Audi Q7, Infiniti JX and Volvo XC90.

What’s puzzling is why it’s taken Lexus so long to launch a 3-row crossover. The RX is the brand’s most popular model and a 3-row crossover has been the number one demand from dealers for several years. Cadillac is another luxury brand that’s been dragging its feet when it comes to 3-row crossovers.

The L.A. Auto Show opens its doors to the media on November 29. To follow our coverage, head to our dedicated hub.