The scene has been played out so many times as to border on cliché. It begins with an impromptu meet-up of two Chevy Camaros, each announcing its prowess with a V-8 rumble. Then, despite good-natured banter between the drivers, an unspoken challenge is made. Finally, a tire-smoking showdown ensues.One big difference this time: the encounter, which took place at summer’s end, did not begin on the main drag of a small Midwestern town and pursue resolution on a deserted country road. Instead, the Camaros, a pair of pumped-up early ’70s models owned by friends, faced off at the Azadi Stadium Race Track in Tehran.The setting was a gathering of the Tehran Café Racers, but aside from a few minor details — Persian lettering on the license plates and on the cans of Coke sipped over lunch — it could have taken place at any number of racetracks in America. The loose-knit group, an affiliate of a club based in Florida, is part of Iran’s enthusiastic classic car culture. Vintage Detroit models play a big role in the activities, and driving events take precedence — the track session was the group’s first since its founding earlier this year.