Parking at the border is very difficult on the US side. Consider parking at a Metro Station then taking the Blue Line to San Ysidro. Metro cards (Pronto!) are available at all Metro stations ($2 for the card plus the cost of each ride). The Metro stop immediately before San Ysidro is Beyer Blvd. Give yourself 45 - 60 min to park and cross into Mexico. New border crossing requirements meant US citizens must cross into Mexico (all the way across the walking bridge) and the tour guide meets the group at the bottom of the bridge. Its a short walk - maybe 5 - 8 min. Before you leave the US, be certain you check with Border Patrol for any new and unexpected requirements for US citizens to return from Mexico. We crossed both ways with a US Passport and COVID vaccine card. Unvaccinated persons may have testing requirements - check BEFORE you leave US soil! Be ready to walk / stand for 4 - 5 hours in Tijuana. You can shop with MXN (pesos) or USD (dollars) and bring a bag or backpack to bring your stuff home. Money exchange options are available at the border (US side). Do not flash cash or use big bills for your own safety. Understand the exchange rate if you use MXN. All Tijuana stores and restaurants will negotiate (even if you don't think they will). The tour was very enjoyable. We took a Tijuana taxi van to downtown, walked around for a few hours, then took a taxi van back to the border. We stopped at historical sites, tourist sites, for tacos (excellent food), margarita and tequila tasting, and shopping. The tour guide takes several group photos (presumably for marketing purposes). The stops are pre-arranged and the businesses were expecting us. It was very efficient and we were in and out despite being a group of 9 (3 couples who didn't know each other before that day). Our tour guide spoke fluent English and Spanish and lead an informative tour. The wait to walk back into the US was long and we were glad were in a big group. Many panhandlers, vendors, and begging children will likely approach you in line at the border. We were warned to NOT accept any offers to "skip the line on a bus" because they were scams. You can get food from walking vendors while you're waiting in line to go back to the US. The food is quite good and the vendors are mostly honest. If you give money to panhandlers or children, more will come and ask for money too. They may even swarm around you if they see money. Don't give money to anyone but a vendor, use small bills ($1 or $5), and don't flash cash or flip through a wad of bills. The tour was excellent! Despite the ad indicating the trip is 4-5 hrs, the time needed to park, walk to Tijuana, and return to the US will make this an all-day event. The tour is worth the cost and very, very enjoyable. Our guide was Humberto and he was outstanding!