In spite of a previous assassination attempt on Roosevelt while riding in a Buick convertible, the president still famously enjoyed appearing in the Lincoln as an open car in parades and public gatherings.
After the Japanese attack on Pearl Harbor, the Secret Service began to express concern over potential assassination attempts on the president, as his limousine was not armored and had no protective features.
The Secret Service did not use Al Capone's car for his visit to Congress at the United States Capitol on 8 December, in spite of the myth even being featured in the History Channel documentary Pearl Harbor: 24 Hours After.
[5][6] The Sunshine Special was modified to be capable of protecting him, with armor plating for the doors, bullet-proof tires, inch-thick windows and storage compartments for pistols and sub-machine guns.
Although some sources allege the Sunshine Special was transported to the wartime Tehran, Casablanca, Malta, and Yalta conferences during World War II, there appears to be no evidence to confirm this.