Cabin looks to be based on the latest 3 Series' interior

The BMW 4 Series convertible has been spied again, this time revealing not only its exterior, but also giving us our first look at its interior.

Externally this latest prototype is wearing the same amount of camouflage as earlier vehicles. In terms of proportions, the upcoming 4 Series will stick to a well-worn path with a three-box design and a long bonnet.

As revealed in previous spy photos, the new car looks to be first 3 Series/4 Series convertible in two generations to feature a fabric roof.

While it may not offer the same level of protection from the elements and ne'er-do-wells, the folding soft-top will likely have fewer styling compromises, improved storage space and a lower overall weight.

Our first glimpse of the cabin shows it to be, unsurprisingly, similar to the 3 Series. Ahead of the driver's there's a three-spoke steering wheel and a customisable digital instrumentation screen.

In the centre of the dash there's a large infotainment screen, a compact climate control setup, and plenty of metal-like highlights.

Under the bonnet we expect to see a selection of turbocharged four- and six-cylinder engines shared with the latest 3 Series range.

It's possible the new 4 Series could also feature a three-cylinder turbo at some point, and a hybrid is probably part of BMW's game plan too.

Nothing's been confirmed yet, but we expect to see the 4 Series cabriolet make its debut either later this year or early next.