Seoul - Not many cars available but used it a couple of times. From the Marriott Renaissance to ICN was reasonably priced.

Beijing - A6's the several times I used them. Sometimes few and far between especially the further you get out on the ring roads.

Shanghai - A6's again and a lifesaver in the Bund area. Never a problem getting a car. Quick and inexpensive.

Berlin - It was last year but I hear they may not be there anymore. - BMW X5 at the time.

Seattle - Great service in and around the city and to the Airport

NYC - Every 2nd car is a UBER Used UBER 9 times last week. Got a Suburban each time (requested Black Car) Driver said since Lincoln discontinued the Town Car drivers are moving to Suburbans

Also used in:

Miami
SF
Minneapolis

For me it's kind of like Starbuck. A consistent service where you always know what you are getting (I only use Black or SUV)