Could Porsche be going ahead with a four-door Panamera Cabriolet? An Autocar report suggests so, even provides these sketches as proof.

Autocar alleges that Porsche is planning on building a four-door Panamera Cabriolet. These sketches supposedly belong to a patent application filed in the US. Rumours of additional Panamera models have been doing the rounds since even before the car was launched and of course a cabriolet was also mentioned.

As depicted in the images, the four-door layout has been retained, which means the car would be a 5-metre drop top with the same interior space as the standard model. Therefore some technical trickery would have to be employed to keep it structurally rigid, including a strengthened A pillar. Even more wizardry would be employed to keep it as good a handler as the tin-top versions.

Porsche is on record saying it needs to increase sales substantially over the next few years and one sure way of doing that is to introduce new models. Speculation currently surrounds a smaller SUV to fall under the Cayenne, an entry-level new "356" and at least one more variant of the Panamera.

Competitors are not selling four-door convertibles at the moment so such a gamble, if Porsche ever took it, could either paint the company as a forward-thinking pioneer or bite it on the backside.