Can we ever know how many Uber and Lyft cars are really out there?

Rideshare companies Uber and Lyft are concealing data regarding the number of vehicles on the streets in San Francisco. These ridesharing companies avoid giving out any information because of their ongoing battles with each other, the city, and taxi driver unions, as well as the fact that both companies do not wish to give out any information to the public. Withholding the number of ride-for-hire cars creates great difficulties for city planners who must attempt to estimate how many cars are actually out on the streets. Lyft’s national accounts manager says that the company’s end goal is to reduce car ownership, but gave no specifics on their goals for the total number of Lyft drivers. How many ride-for-hire cars do you think are in New York City?