The next iteration to BMW's mid-size luxury car line, the 2017 BMW 5-Series, has been spied on while undergoing road tests in Europe.

Heavily camouflaged prototypes of the new 5-Series saloon and Touring models, with codenames G30 and G31, respectively, have been seen on a number of German roads and racetracks. Recently, Motor Authority's spy photographers have managed to capture several photos of the upcoming vehicle.

The German automaker's next-gen model to utilize the carbon fiber-infused modular platform known as the "35up" will be the 2017 BMW 5-Series. The platform debuted in the 2016 7-Series flagship sedan.

These newest spy images reveal that the model will have evolutionary design elements with a familiar façade that adopts a more conventional angel-eye headlights and a more prominent grille.

Although the exterior apparently won't have remarkable changes, photos of the car's interior shows that it will have a new steering wheel and digital instrument cluster along with a freestanding infotainment system.  Wood trim, revised switchgear, metallic accents, and a large iDrive controller are also evident.

Due to its lightweight structure, Motor Authority expects that the new 2017 BMW 5-Series will weigh about 220 pounds less than the present model. It could end up weighing only 3,300 pounds or less.  If accurate, it means that the upcoming model will be the series' lightest version yet.

Moreover, the spy shots show that the car's size and proportions seem to take a lot of inspiration from the current sixth-generation model. If that's any indication, the upcoming version could have an overall length of roughly 16 feet and width of a little over six feet.

The unannounced model's engine options will mimic the 2016 7-Series, WorldCarFans.com noted. As such, we can expect a diverse range of diesel and petrol options such as a 3.0-liter TwinPower Turbo six-cylinder petrol with 326 PS (240 kW) and 450 Nm (332 lb-ft) of torque, another 3.0-liter TwinPower Turbo six-cylinder diesel with 265 PS (195 kW) and 620 Nm (457 lb-ft) of torque, as well as and a 4.4-liter TwinPower Turbo V8 with 450 PS (330 kW) and 650 Nm (479 lb-ft) of torque. 

An entry-level version with 1.5-liter three-cylinder diesel engine is also expected, along with a plug-in hybrid variant that packs a 2.0-liter TwinPower Turbo four-cylinder petrol engine which comprises of an electric motor and a lithium-ion battery.

Other tech innovations that the new 5-Series is said to offer are a self-parking system, a gesture control interface, and digital instrument cluster just like those found on the larger 7-Series model.

The 2017 BMW 5-Series sedan will reportedly debut during the first half of 2016 and it is expected to go on sale the following year as a 2017 model.