When is an M car not an M car? When it's an M Performance car.

The lack of anything but the original M badge on a fast BMW may throw the fans of the Bavarian brand into an angry frenzy, but the reality is that not everyone in the world wants a hard-core sports sedan.

BMW knows this, and that's why the M550i xDrive exists alongside its brothers — the M5, M5 Competition, and the M5 CS.

Now available locally for the first time in right-hand drive from ATL Autobhan, the M550i xDrive is designed to bridge the gap between the non-sports car types and the hard-core, go-fast enthusiasts.

On the surface the M550i xDrive looks like the typical 5 Series sedan, inoffensive and mature enough to fit into any executive parking lot, especially when less brash colours, like Alpine White, are chosen.

Get closer and there are small hints that the BMW faithful might take note of such as the M aero package, 19-inch wheels, and massive brakes behind them. Again, nothing technically special that a regular 5 Series couldn't be equipped with.

The interior is typical BMW, packed with the latest technology and luxury features. So for the buyer not seeking the attention a normal M5 would they can putter around ensconced in comfort and fly under the radar.

The brilliance of the M550i xDrive is that should one want to fly over the radar it can do so, literally. Hit sport mode and step deep into the accelerator and the TwinPower turbocharged 4.4-litre V8 blasts to life sending its 530bhp to all four wheels via the xDrive system.

Traction is always maintained, but a standard M sport differential makes sure the rear-wheel drive heritage of the BMW is never forgotten. 60mph is dispatched in 3.8 seconds; fast enough to relegate most rivals to the rear-view mirror, even after they've got over the shock of an unassuming sedan gapping them at the traffic light. When the corners come up, the M sport brakes do their thing with consistency to inspire driver confidence. The grip from xDrive works here as well, while the Adaptive M suspension offers sports car levels of body control.

And when all that performance is no longer needed the M550i xDrive can quickly recede into the sea of other sedans without much worry, leaving its victims plenty confused about where the automotive gut punch they just received came from.