The Lamborghini of the Italian police was a single piece and its use was conceived to patrol a problematic highway in Southern Italy. Of course, that donation was intended for advertising purposes too, despite you all would agree that a company such as Lamborghini doesn't need any advertising and has the privilege to pick its own customers, while most of the other car companies chase new customers. A similar story occurred with Maserati, which donated a Quattroporte ~9 years ago as official car of the President of the Republic.
The rest of the Italian police mostly relies on Italian cars, such as FIAT and Alfa Romeo, despite they also have non-Italian providers, such as Toyota. The largest amount of cars to be used for highway patrolling and pursuit are heavily tuned Alfa Romeos. Same story is for the Carabinieri, the military branch of the Italian police service.
I'm aware that the German police has several Porsches for pursuit purposes.
In general, I think that having the possibility to drive high performance cars (starting from tuned ones, it's not a matter of luxury but of acceleration, handling and top speed) is necessary.
