San Diego Police prepared for President Donald Trump’s Sept. 18 visit by posting dozens of temporary “No Parking/Tow-Away” signs on downtown streets to clear the way for the presidential motorcade.

Drivers who didn’t move their cars were ticketed and towed, and paid at least $250 to free their vehicle from the tow yard.

But SDPD now acknowledges that some of those no-parking signs were too small and did not meet the city’s own guidelines for no-parking signage and towing during special events.

The department “...failed to meet the expectations of the community in this situation… and we apologize,” Lt. Shawn Takeuchi told NBC 7.

Devon Walker's car was towed from its parking spot near 3rd Avenue and B Street early on the morning of the President's visit.

Walker told NBC 7 she is sure there were no tow away warning signs on that street. She also said at least two other vehicle owners had their car towed.

Walker said she lost at least three hours of work getting her car back from the tow yard. She paid $250 in tow fees, and also got a $52 parking citation. Walker filed a claim against the city to get those fees back, and will fight the parking citation.

"It was a whole lot of lost wages for me," Walker said. "I didn't plan to be (away from work) for three, almost four, hours to go and get my car. (SDPD) pretty much interrupted peoples' lives."

An NBC 7 assignment editor spotted the problem signs as the President Trump’s motorcade rolled through downtown before and after a fund raising event at the U.S. Grant Hotel.

Station photographers shot video and still photos of the deficient signs, which lacked some or all of the required information, including the name and date of the event, a contact phone number, and the letters “SDPD” to confirm that the no-parking order was properly authorized.

An SDPD spokesman told NBC 7 the department improperly towed seven vehicles that day, including three cars parked on Third Avenue, two on A Street, and two on Ash Street. The red lines along streets in the map above indicate where invalid signs were posted.

The city’s guidelines for special event parking restrictions require a minimum size and style for the signs and the printed “No Parking Tow Away” warning message. NBC 7 found at least four examples of no-parking signs that did not meet those requirements, including one that consisted of a piece of white paper that read only “No Parking 5 am to 5 pm” and was taped around a small traffic cone.

An SDPD spokesman said anyone who parked near the invalid signs on Sept. 18 and had their vehicle towed should request a claim form from the city’s Risk Management Department at 619-236-6670.

The claim form, which must be submitted to receive a refund, is also available online.

Information about how drivers can challenge the $52 illegal parking citation they were also given is printed on the back of that citation.