Ok, it's been two weeks. The missing report was unsuccessful since we can't track down the cars because the package has been brought in by hand to the post office in Berne. So there are no records of who the actual finder of the package was. And also (since it's been mentioned) involving the police makes no sense since the value of goods is only 10 Euros and the swiss post is eager to pay for the loss anyway. - It's quite a stupid and sad situation, but there we are.
Hence my question: Should it stop here, or should we buy another Viper model and send it further on together with the postcards?