R-D
I could never imagine the French police riding German cars, Porsche or any other make: jamais de la vie, Monsieur! So your picture comes like a shock
What I can remember from the streets, only French cars were used by any French services, police, guards, army etc. In 60s and 70s, the best example of what the French Police used is shown in the movie series with Louis de Funès, such as
Le gendarme à Saint-Tropez.
In the 80s Renault Alpine A310 were bought to serve the purpose of catching the speeding drivers, but there were rather few and I never saw one.
In another, quite recent, movie series
Le Taxi you can see that the French innovation gives a new
spiritus movens to the ubiquitous Peugeot that defeats Mercedes cars and proves that l'impossible n'est pas français...
But more seriously, today the French police has invested in Subaru Impreza WRX and this is the new toy that allows them to have fun on motorways.
BTW, a French car maker PGO offers cars that ressemble a lot the Porsche on your picture. Have look
http://www.pgo.fr/en/