The Petermann family decides to take a family vacation to the sunny south. The Petermanns are grandfather, father Max, mother Biggi, children Stupsi, son Andy, and pretty Monika, Max Petermann's sister. They rent a speedy sled because Max Petermann has just gotten his driver's license. Not only are there various starting difficulties due to a lack of driving experience, but there is also a special case with the car: hidden deep in the upholstery are secret documents that a trio of gangsters are trying to smuggle abroad. A mix-up of the license plates causes some turbulence. Willi Polz is assigned by the trio to keep an eye on the Petermanns in order to secure the documents at the right opportunity. Of course, something always gets in the way on the trip to Bella Italia. The fact that Willi falls in love with the blonde Monika is the least surprising thing. But the grandfather's actions are the real sensation.
