As noted here with the collectibles, there are some interesting things to find in Mafia: Definitive Edition’s open world. The five hidden super cars are a good example since their existence isn’t obvious. First, go to Bertoni’s Autoshop. You’ll find a number of postcards on the wall which indicate the different locations of each super car.
Keep in mind that you need to collect these cards, or else the super cars won’t spawn. Start with the Disorder, which is found east of Flyer Dam in a building. Next, go with the Trautenberg Sport – it’s on the waterfront in Downtown. Then there’s the Lassiter V16 Appoleon, located in the central mansion on Beech Hill.
The Flame Spear is found on Central Island in the southeast construction site and the final car, the Manta Prototype, is in the central rail station of Works Quarter. However, there’s another car that can be unlocked by completing a very interesting mission.
Head to Salieri’s Bar and you’ll find a note telling you to head to Little Italy’s west-most point. Once there, answer the payphone and a timed mission will become available. Your job is to drive the Crazy Horse to the location on the map and it must be undamaged. Do this and the Crazy Horse is yours.
One other neat detail in Salieri’s Bar is being able to access the armory. This is perfect for stocking up on weapons so head to reacquire any of your favourite firearms.