We love a good story about a new Dartz vehicle, but different special editions of the Prombron were starting to all look the same. The Nagel is an entirely different story. Designed in cooperation with the naval design house Gray Design, the sedan-bodied version of the Prombron is intended to be used to tow your boat. The Nagel is capable of towing a craft up to 15 meters long and weighing up to five tons. It is also, of course, bullet proof.