BMW M3 And M5 Rear Doors Proudly Flaunt Race-Bred Arches

Take a close look at the latest BMW M3 and M5 saloons and you might notice something a bit unusual: the rear doors don’t quite follow the line of the rear wheel arches. What can look like an odd styling mismatch at first glance is actually a deliberate detail, signed off by BMW M boss Frank van Meel himself. Rather than smoothing everything out with bespoke rear doors, BMW has chosen to let the widened bodywork stand proud and give its fast four-doors a more muscular stance.

The reason lies underneath the skin. Compared with the standard 3 and 5 Series, the M3 and M5 use wider rear axles to cope with their extra power and grip. To cover that broader track, BMW stretches the rear arches and fattens up the body, but keeps the regular rear doors. The result is a visible step between the edge of the door and the flared arch – a look some rivals, such as Audi’s RS models, avoid by designing new doors to match their wider bodies.

Van Meel sees that contrast as a core part of the M saloon’s personality. He likens the 25mm wider body with unchanged doors to something you might see on a race car, where the arches are clearly pulled out to cover broader tyres. To him – and, he argues, to many M customers – that slightly raw appearance makes the car look more purposeful. You can almost “see the power” in the way the rear bodywork bulges beyond the door line, rather than disappearing into a smooth, seamless shape.

It also helps set the M3 apart from its coupé sibling. The M4’s lines flow more cleanly as the body swells over its wheels, giving it a softer, more elegant profile. The M3, by contrast, wears its extra width more obviously, and that has become part of its story over several generations. BMW could easily tidy it all up with fresh rear doors, but for now, the brand is happy to let its high-performance saloons wear their broader arches proudly, even if it means the rear doors will always look just a little unconventional to keen-eyed observers.