I don't know for certain, but I believe it's merely a light bar height booster. I think it's just so the police lights are higher up and can be more visible in traffic.bootymac wrote: But what's up with the top hat?
Japanese police and ambulance sirens are much quieter than American ones and use a lower tone. They are far less obnoxious than what the Americans use (trust me, I hear them everyday in DC). For this reason, I think they value light bar visibility more than in the US and other countries.
The Japanese police and ambulances also use speakers and often speak to motorists asking them to yield or stop to let them pass. The police will also call out your vehicle when pulling you over. They will say things like "White Honda Fit, please pull over."
Interestingly, they often say "please" and "thank you" over the speakers. I'll take that any day over the screeching ambulance sirens I hear daily in downtown DC that are so loud, they actually hurt your ears.