San Diego Comic-Con may still be weeks away, but one of the surest signs that con season has officially arrived is already rolling through the city. Every year, the arrival of the first MTS trolley wrap serves as an unofficial countdown to Comic-Con, transforming San Diego’s public transit system into a moving preview of the pop culture spectacle to come.

For many attendees, spotting that first wrapped trolley is the moment SDCC starts to feel real. According to Mark Olson, Director of Marketing & Communications for the San Diego Metropolitan Transit System, that’s true for MTS employees as well. “Trolley wraps are often the first glimpse of what fans can expect for the upcoming Comic-Con experience,” Olson told us. “And just like fans, MTS employees start to get excited about it too when that first wrapped Trolley heads out into service.”

This year, Comic-Con trolley advertising inventory has completely sold out, with all 45 trains serving the Convention Center and Comic-Con area receiving wraps. While plans are still being finalized, attendees can expect approximately 15 unique sets of artwork, including several trolley cars featuring interior advertising as well.

Olson says Comic-Con remains an all-hands-on-deck effort for MTS. “We are fully staffed and excited to be a part of the festivities as the Comic-Con experience for many attendees begins on the Trolley,” Olson said. “Attendees are often traveling a long way to attend, so we want to contribute to the fun, positive experience that so many people have enjoyed over the years.”

MTS is also teasing additional Comic-Con activities this year, including activations at the Gaslamp Quarter and Convention Center stations, a new collector pin, and giveaways for riders at select stations throughout the convention.

[UPDATE June 8]

Leading off this year’s wraps is Godzilla Scramble, a new set of Godzilla blind box figures from Toho and Bandai Namco Toys & Collectibles America, as well as Godziburst, a new toy line featuring monsters from the Godzilla franchise sorted by elemental “Burst Types”.

From MTS, here’s a look: