Los Angeles’ two NFL teams will play in the same city on Sunday for the first time. So we asked locals, who will they be rooting for?

LOS ANGELES — The Los Angeles Rams trailed 13-7 at Los Angeles Coliseum on Sunday, and Robert Murillo, a season ticketholder, said he was worried. Not about the score.

“Every time I turn on the radio these days,” Murillo told USA TODAY Sports, “I hear the Chargers promoting themselves.”

That would be the Los Angeles Chargers — sorry, San Diego — and Sunday heightened the battle for L.A.’s NFL fans. It also created a challenge for an intrepid reporter (yours truly) intent on seeing two games being played almost simultaneously and 12 miles apart.

The day started at StubHub Center in nearby Carson, where the Chargers, making their regular-season debut in Los Angeles, played the Miami Dolphins. But the early action was in the parking lot.

In a city of about 6.5 million cars, the Bolt Bus that pulled into the parking lot at StubHub Center is a one-and-only. Once a school bus, it now features Chargers seat covers, a Chargers helmet painted on the ceiling, a Chargers flag atop the roof, Chargers stickers everywhere and BOLT BUS license plate.

For the last there seasons, during Chargers home games, it’s been parked at Qualcomm Stadium in San Diego. But now it’ll be in Carson, the bus relocating with the team, and arriving early Sunday for the Chargers’ regular-season debut.

“I’ve been a life-long Chargers fan since birth,” said Bart Hancock, 56, the owner and driver of the Bolt Bus and a resident of Orange County. “It was a lemon when I bought it. Now it just purrs.”

But Hancock squawked at the parking prices — $75 a game, compared to the $40 he paid in San Diego.

“It’s a greedy, greedy sport,” he said. “The owner wants every last shekel they can get. That’s why they left San Diego.”

But suddenly Hancock discovered something more reprehensible than the parking prices — a giant Miami Dolphins flag.

“That is a monster,” he exclaimed. “Oh, my God. They’re taking over.”

Los Angeles Dolphins, anyone? Truth is, the Chargers fans had them outnumbered, especially in a stretch called “Thunder Alley.” It’s reserved for six…