Semi-official BMW tuner Alpina has given the world some fantastically tweaked cars over the years, the latest of which is the 600-horsepower B7 based on the 7-Series.
As you may have noticed, Alpina tends to step where BMW's own tuner, the M division, doesn't dare tread, and it looks like the next offering will be based on the X7.
In an interview with Automobile published last week, Alpina CEO Andreas Bovensiepen confirmed that an Alpina X7 is being tested. He didn't provide any additional details but the recently revealed B7 likely provides some clues.

2019 BMW Alpina XD4
The B7 packs a 4.4-liter twin-turbocharged V-8 conservatively rated at 600 horsepower and 590 pound-feet of torque. It also features a sport exhaust, a reworked 8-speed automatic transmission, and track-tuned suspension. All of these features installed in the X7 would make for an impressive SUV, and don't forget that Alpina offers tuned versions of the X3 and X4 overseas, so the company has some experience working on SUVs.
Right now the hottest X7 is the BMW X7 M50i. The M Performance model is powered by a 4.4-liter twin-turbocharged V-8 rated at 523 hp and 553 lb-ft. It needs just 4.5 seconds to hit 60 mph, so imagine what a 600-hp X7 will do.
In the same interview with Automobile, Bovensiepen also revealed that an Alpina-tuned 8-Series Gran Coupe is being studied. It would essentially fill the void of Alpina's previous B6 Gran Coupe.