This month saw auto manufacturer BMW take over ownership and control of Alpina, the aftermarket BMW tuning company that has been closely associated with the Bavarian carmaker for decades. It's unclear exactly how things will change for Alpina post-2025, as electrification will likely be introduced at that time, but until then, the tuning company still has a number of exciting, electrification-free products on offer. Among them is the Alpina B4 Gran Coupe, essentially Alpina's more powerful version of the regular BMW 4 Series Gran Coupe. We first caught spy shots of this new model in August last year, with updated images arriving two months later, and now it's almost ready to be revealed.

Alpina teased the arrival of the new model this past weekend, using a shadowy image of the car's rear end to whet our appetites for its full reveal. The image shows that we can expect the typical Alpina badges and decals, as well as a subtle trunk lid spoiler and, possibly, smoked taillights.

But thanks to spy shots that hit our inbox this week, we can confirm a little more. For a start, the B4 is definitely getting some drilled brake discs and beefier calipers. Alpina's trademark Green Metallic hue will also be offered. As is customary, a quad-exit exhaust system will be fitted too.

As for other changes, it's quite likely that Alpina's decision to drive this development vehicle around without camouflage suggests nothing but a yet-to-be-revealed overhaul of the styling. The wheels you see here will certainly not be offered - expect options with vastly more spokes - and the bumpers will be updated to differentiate this from a regular 4 Series. To that end, we expect spoilers at each end's bumper and a better design for the exhaust trim appliques at the rear, the aforementioned trunk spoiler, and a host of interior luxury enhancements. Alpina badges will replace the BMW ones, and stripes will feature too.

As for performance, we're expecting the Alpina B3's 3.0-liter turbo straight-six to be fitted, sending 462 horsepower to the road via an eight-speed automatic. More details will be revealed shortly, with a full launch expected in a few weeks.