Police Car? Or Civilian?

This is something that struck me as strange.

The other day, I saw a couple of Singapore Police cars which were being driven by people in civilian clothing. What's more, there was always someone in the passenger seat.

Now, this I found puzzling. Maybe they were undercover. But then they were broadcasting that they were cops by driving around in a Police car.

Maybe they were not undercover, but were on leave. In which case, shouldn't they be driving their own car?

So if I need help, are they the right people to ask?

Maybe that's not such an important thing cause Singapore is a really safe place.