I could waste my time and post a photo of every single vehicle, be it GCPD car, Osh-Kosh truck, etc. they used in Pittsburgh, LA and NY to show you that the DKR plates only had 2 holes in them...but you're going to have to take my word for it.
All the DK plates have 4 holes, the DKR's have 2. The white surround at the bottom is another difference.