It has only been about a month since we first caught a glimpse of BMW->ke178 out testing its next-gen 5 Series sedan, but a more recent batch of spy shots shows that the automaker is putting some more miles on the 2017 BMW 5 Series on some frozen, snowy tundra.

Very little has changed between the two prototype spottings including the fact that both cars seem to have a small door on the left front fender suggesting that they are plug-in hybrid->ke147 models. Despite this similarity, though, each car utilizes a different exhaust design with the latest example getting two outlets on the driver's side of the car rather than the previous prototype that had one outlet on each side.

Aside from the different exhaust pipes, these cars appear to be the same, although the heavy camouflage still makes it hard to get any real idea of what the car will look like. The styling elements we can discern (mostly consisting of the roofline and the general shape) suggest that the design of the 2017 5 Series will certainly be an evolution of the current car rather than a groundbreaking new look.

There’s no doubt this new 5 Series will carry cues from recent BMW introductions including a larger, more upright kidney grille, wider headlights that stretch toward the grille and a new taillight design with more expressive lighting elements. As for the rest design, your guess is as good as ours.

The big differences between the current 5 Series and the new 2017 model will be what’s under the skin including the addition of the plug-in hybrid variant. This includes an all-new platform that will help this sedan shave around 200 pounds of curb weight, but downsized turbocharged engine options will continue to balance performance and efficiency.

There is still no word as to when BMW plans to unveil the 2017 BMW 5 Series, but we will probably have to wait until late 2016 to see it on the road.

Click past the jump to read more about the 2017 BMW 5 series.

Why it matters

More spy shots of the 2017 BMW 5 Series show that the automaker is continuing to test prototypes of its next-gen sedan including what would appear to be a new plug-in hybrid model.

2017 BMW 5 Series - spy shots