Updated at 5:13 p.m.

A San Francisco-based car sharing service is facing off against City Hall as it prepares to launch this Thursday in defiance of the city's licensing office.

Lyft's unique model relies on regular people essentially becoming chauffeurs in their own vehicles, picking up passengers who request a ride through the mobile app. The service -- known for its signature pink mustaches -- has already launched in more than 20 cities, including St. Paul.

Minneapolis officials told the company several months ago that the model qualifies Lyft a taxi service under city ordinances. That requires the vehicles and drivers to be licensed and inspected as taxis, which clashes with Lyft's business model.

Lyft spokeswoman Paige Thelen said on Tuesday morning that they planned their Thursday launch because "after productive conversations with city leaders, there has been recognition that Lyft's peer-to-peer business model cannot be easily defined by the existing framework for taxis and for-hire vehicles."

But the city's head of business licensing, Grant Wilson, said they will enforce city taxicab regulations if they see Lyft cars operating around town. They have already towed three vehicles operated by UberX, a similar company that Wilson said launched about a month ago in Minneapolis.

"We intend to provide the same enforcement if we find Lyft vehicles operating in the city, picking up passengers as if they were a licensed taxicab," Wilson said. "We will ticket the driver, ticket the company, and impound the vehicle for not having commercial insurance."

Lyft says it carries insurance, but Wilson said they have not provided a copy to any government agency.

Wilson added that a regional group of regulators has been actively discussing these car sharing services, and may have a metro-wide regulatory program in place that could accommodate them by June.

Prior to Wilson's comments, Thelen said service in Minneapolis will begin on Thursday at 4 p.m., which is when users will be able to request a ride through their smartphones. Thelen said they already have a cohort of Minneapolis drivers ready to start.

Their goal is to use cars more efficiently, reduce the need for car ownership and build a community. "Lyft is more than just a ride from point A to B. It's about interacting with your driver, meeting new people and building relationships offline," Thelen said.

Once someone has found a driver through the app, a picture of the driver and their vehicle are displayed on the phone. Thelen said the Twin Cities driver community includes archeologist, an opera singer and a children's book author.

Upon reaching their destination, riders are given the prompt to make a "suggested donation" based on the time and distance of the trip. They can increase or decrease that payment as preferred.

Some big issues that have arisen in other areas revolve around background checks and insurance. Thelen said drivers are required to undergo a background check, driving record check, a phone interview and a 21-point vehicle inspection. The company provides $1 million in excess liability insurance. See the full safety rundown here.

Lyft's official Minneapolis launch party is on Thursday at 6 p.m. at 1400 12th Ave NE.

Pictured: A Lyft vehicle in San Fransisco (Colin Covert)