The CPUC set the TNC trade dress rules in place this past Summer 2014. To those ride app drivers who refuse to use a proper trade dress, they risk receiving a $1000 fine for violating CPUC rules.
The three most popular ridesharing providers in San Francisco, Los Angeles, and San Diego, California are UberX, Lyft and Sidecar. Trade dress identifies which platform ridesharing drivers are affiliated with while performing ridesharing services. The CPUC set the terms and conditions of trade dress under the TNC(Transportation Network Companies) umbrella.
For Uber, a paper "U" affixed on the right lower side of the windshield is the approved trade dress. Sidecar trade is an orange sock-like sleeve (MOX) that reads, "Sidecar" and is draped over side driver and passenger side mirrors. The designated trade dress for Lyft is a furry Pink mustache that is attached to the front car grill. There are a small percentage of Uber rides still using the "U" light.
An unapproved trade dress is still being used on some Uber rides operating in San Francisco. This "U" light is no longer permitted on Uber vehicles. We assume the Uber drivers continuing to use the "U" lights are ignoring the TNC rules or are uninformed of this previous change. Based on constant communication sent from Uber, this is highly unlikely.
The approved trade dress for Uber is a black and white paper "U" that is required to be attached to the lower right windshield inside active vehicles. Whenever ridesharing drivers go online, this Uber "U" must be visible to clients. Wear the right "U" trade dress to avoid fines.