They are showing Isle of Dogs tonight. They have a San Diego showing at Waterfront Park (Little Italy area)
Our Summer Movie Night Series is back this week! Join us in select cities for tonight’s showing of Isle of Dogs Movie, plus popcorn, giveaways, and pre-show entertainment. Activities start at 6PM, with the movie beginning at dusk, and it’s all free! More details at amazon.com/treasuretruckmovieseries
It seems like it's FCFS, but I did get a notification from the treasure truck last weekend, since I live in the Austin area. I don't know if you have to get tickets that way, or can just show up. Austin has an Eventrbrite link, but it says that the ticket is not necessary. If it was any other weekend, I would totally go!