A-Class siblings get the new A45 AMG's upgraded turbo engine, and much more speed Last month, Mercedes-AMG announced the A45 AMG would benefit from a more powerful engine, its 2.0-litre turbo upped from 345bhp to 381bhp ' a move completely unrelated, of course, to the arrival of the 362bhp Audi RS3.

Now comes the turn of the A45's siblings. Merc has given the CLA 45, CLA 45 Shooting Brake and GLA 45 - which all share the A45's platform ' this new, more powerful version of the 2.0'litre engine, making them all suitably rapid.

So yes, both CLA 45 and GLA 45 now have 381bhp and 475 Nm of torque to play with. The seven-speed dual clutch automatic gearbox also gets new ratios ' 'familiar from the Mercedes-AMG GT', we're told ' allied to that four-wheel-drive system, meaning yet more speed.

How much speed? Well, the CLA will go from 0-100 km/h in 4.2 seconds ' just under half a second quicker than before. The CLA Shooting Brake does it in 4.3, while the GLA 45 records 4.4 seconds. That's supercar pace.

All get the 'dynamic select' as standard with four driving modes, and the option of 'dynamic plus' which brings in a mechanical front locking diff.

We're not quite sure what list of new-car requirements might lead you to purchase any of this niche-busting trio, but still, we're glad they exist.