The X4's hot sibling is just around the corner and we now have pictures of the pre-production model testing.

The more aggressive front fascia, larger air intakes, chunkier side skirts, and quad exhaust tips all say to us that this test model will eventually become the X4 M.

The motor is rumored to be a new S58 3.0-liter twin turbo straight six, churning out some 455 or so hp.

With the engine also expected to find its way into the X3 M, they should be more than enough competition for Mercedes-AMG's GLC63 S, even though the latter has 8 cylinders and as many turbos.

Unfortunately, we don't quite know when all of these M SUVs will be released because aren't even quite sure when their base counterparts will launch.

Whenever that happens, though, they should be good for some surprising lap times.