Mercedes Aircap is no fun for dogs

We wouldn't trust even the best-behaved dog in the world to just sit in the back of an open-top car without making a jump for it.

But in this promotional video for the new Mercedes E-Class Cabriolet the main thing concerning this dog is getting the wind in his ears, and he's not best pleased with Merc's new Aircap system.

We're not denying that Aircap works; reports suggest it really does deflect the airflow over the cabin.

But its worth remembering that its also a dirty great bit of plastic sticking out of the windscreen of your otherwise streamlined motor, and that can't be good for fuel economy. (And sort of cancels out the fact that the E-Class coupe, on which it's based, is one of the most aerodynamic cars on the road).

Moral of the story? Aircap will nark your dog and drink your fuel, but passengers in the back will probably thank you for flipping the switch.