At some point I’m going to regret not buying these excellent Batman vehicles from The Batman Automobilia Collection. This is the 1960s Batman television show version of the Batcycle.
From the excellent Batman Automobilia series comes a diecast version of that Batmobile featured in Detective Comics #219.
According to the always authoritative BatmobileHistory.com,
When Batman & Robin see several known criminals driving around in old cars in Detective Comics #219, they deduce that something is about to happen and decide to investigate. Their investigation takes them to a classic car convention in the town of Millville. To keep with the spirit of the festivities – where all modern cars are forbidden – Batman temporarily replaced the then-current Batmobile with this car. Based on the 1905 Marmon, it featured a Bat Mask on the front, a pair of door insignias, and a large fin on the rear. Although the car performed admirably, Robin was glad to get back to their “modern” Batmobile at the end of the story.