For a while now we’ve been reporting about the prospect of there being a four-wheel drive version of the new BMW M5. According to our sources, this was a model that was going to be made available in certain markets as an adjunct to the rear-wheel drive car that we’ve driven, and been so impressed by, this week.

Well here’s the news – the 4WD model isn’t and never was going to happen. Speaking to various engineers from BMW on the M5’s international launch this week, the notion of a 4WD version is, in fact, a complete fantasy. For although BMW’s M Division built a prototype 4WD car, the reality of a production version never got further than that.

How so? Why, if they went to the trouble of building a prototype, won’t they eventually make a showroom 4WD model? Because that’s what prototypes are for; to assess what’s possible and what’s not when it comes to the production process. And the packaging of a driven front axle beneath the new M5’s busy new engine bay is, by all accounts, so complex, so difficult to achieve and ultimately so expensive to engineer, it’s now never going to happen.