1928 Cadillac Series 341-A Town Sedan,
The car’s story seems to back up the fact that it was indeed owned by Capone. A 1931 Milwaukee Sentinel story traced the license plates to Mae Capone, Al’s wife.
The complete ownership history of the car is known from 1933 on, and it, too, suggests the car was purchased from Emil Denemark, who took possession of the car when the mobster was in prison as payment for debts incurred from the purchase of a pair of Cadillac V-16s.
The car in question is powered by a 341-cubic-inch L-head V-8 that made 90 horsepower. Cadillac built the first V-8 engine in the U.S. in 1914 and sold it through 1935.
Documentation says Capone had a foundry install quarter-inch boiler plate all around, including under the soft top, as well as thicker windows.
The hinged rear window hinged allowed passengers to shoot at pursuers, and a police siren was added to clear traffic. He also had it painted green and black to match the police car Cadillacs of the day.