Flagship 5 Series has turned PHEV and promises to be BMW's most extreme super-saloon yet Certain cars just define a genre. It’s the Golf for hatchbacks, the MX-5 for roadsters and probably the BMW M5 for super-saloons.But where a current-gen Mazda MX-5 is still a fundamentally similar car to a Mk1 from 1989, the M5 has always been a shape-shifter. At the launch for the new G90 M5, BMW put on a spread of historic M5s for us to drive. Aside from a dozen browser tabs of E34 M5 classified ads, the first thing I took away is that the new M5 is a very, very different car from a 1985 E28. Next to the compact, understated, manually shifted and deliciously slippy original, the latest fast Five might as well have come from a different galaxy.That’s not the salient point, however. More pertinent is that the M5 has always been a technical showcase, and back in 1985 that meant putting a race-derived straight six into an unassuming sports saloon; for the E60 M5 in 2005 it meant a 9000rpm V10, a single-clutch automated manual gearbox and a novel user interface concept; for the F10 M5 in 2012 it meant abandoning 28 years of naturally aspirated engines and embracing turbochargers; in 2018 it meant using four-wheel drive for entertainment rather than stability and understeer. For the F90 M5 in 2024 it means going all-in on plug-in hybrid powertrain technology.