That means a whole lot more practicality, but barely any compromise on performance. The M3's 414bhp V8 remains unchanged, while the four-door weighs in just 25kg heavier than its coupe counterpart. Like the coupe, it'll hit 62mph in a fraction under five seconds, with top speed electronically limited to 155mph.
Stylistically, the M3 saloon is a clear blend of M3 coupe and the more conventional four-door 3-Series.
That front end, with its fat power bulge, flared arches and wide front bumper is lifted near-wholesale from the coupe, but from the A-pillar back things are less extravagant: a bootlid spoiler, reprofiled rear bumper and the obligatory quad tailpipes point to the saloon's M-heritage.
You'll notice the coupe's carbon fibre roof hasn't made the move over to the four-door. We don't mind that - it gives the M3 saloon a bit more Q-car chic than the rather more overstated coupe - but it's an indication that the saloon should be a fraction softer to drive.
That said, BMW has confirmed that the saloon will only be available with a six-speed manual shifter at launch. Expect a dual-clutch automated manual transmission to follow some time next year. The chassis and suspension set-up remains identical to that of the coupe, which suits us just fine.
Of course, with a semi-auto' box and four doors, the M3 saloon is gunning straight for the Mercedes C63 AMG - a twin test we're looking forward to... and that's before the Vauxhall VXR8 (which doesn't have an auto' box, admittedly, but you could always move to Australia) gets involved.
The M3 saloon will arrive in Britain early next year. If you like the look of it, you'd better get onto your BMW dealer quick - the UK's allocation of 700 M3 coupes sold out in less time than it took Jeremy to launch into a rant last night.
