We still can't quite wrap our heads around the idea of a hybrid BMW M5, but the performance saloon will certainly be rocking down to the electric avenue. The "Hybrid Test Vehicle" stickers on the front doors and rear bumper are a dead giveaway, and so is the charging port cap on the front-left wing/fender. The AMG E63 competitor has returned in a new spy video shot while the test driver was enjoying some nice country roads.

Those chunky wheel arches and quad exhausts are indicative of the prototype's M nature, not to mention the massive brakes even for the rear axle. While the test vehicle appeared to have the full production body, it was missing the final headlights and taillights. A subtle boot lid spoiler is tucked away beneath the camo, while the disguise at the front hides a normal-sized grille.

Gallery: 2024 BMW M5 spy photos

As with many recent BMWs, the next-generation 5 Series will switch to flush door handles to create a smoother side profile for better airflow. Those wheels are smaller than what we're used to seeing on an M5 for a good reason – winter tyres. Expect the production version to have a larger set flanking what seem to be beefier side skirts.

Being a hybrid of the plug-in variety, the new M5 should accommodate a fairly large battery pack for a decent amount of electric range. It should adopt the same PHEV setup as the Concept XM, which promised to cover 80 kilometres (50 miles) without sipping any petrol. The two are widely rumoured to use a new S68 engine that could go down in history as the very last BMW V8.

The plug-in hybrid SUV will enter production towards the end of the year and is believed to have around 750 bhp to echo last year's concept. The M5's combined output should be in the same ballpark, which is impressive for sure, but the electric motor and battery pack will certainly add weight. Don't be too surprised if it'll hit the 2,000-kilogram mark (or 4,409 pounds) since the M5 Competition already tips the scales at 1,930 kg (4,255 lbs).

It'll be a long wait for the new M5 since BMW will first show the next 5 Series. Consequently, the range topper is unlikely to go on sale before the end of 2023 or early 2024.