Dubai's taxi scheme mimics the German style minus the coloured roof, hence i understand the confusion.
Taxis in much of the GCC countries are usually bought new. The only exception i could find is Oman since the cars are owned by the taxi drivers themselves, grey imports are super rampant there, and they have (or used to at least) a more lenient laws regarding the cars used. I believe Bahrain is kinda similar in regards to Omani's laws but aside from few US-Spec Sonata's i seen, they all appear to been bought from the official local dealerships.