While you won’t be able to change Lincoln’s outfit in Mafia III, the game does allow you some degree of customization when it comes to your car. Before you can unlock those customization options, however, first you have to recruit Cassandra as an underboss. Doing so is relatively simple, and all you have to do is progress through the story normally until the mission “Old Times’ Sake” leads you to an informant who directs you to her hideout.
Once you’ve recruited Cassandra, check your map for her associates icon. Aside from equipping weapons from Cassandra’s van, you’ll also have the option to customize your vehicle. Simply scroll to the right until you see the tab that says “Vehicle Modifications,” and click on that. You can get suspension upgrades, vehicle armor, a drivetrain upgrade, bulletproof tires, a bodykit upgrade, and a supercharger. However, do note that you’ll need to complete favors for your underbosses in order to unlock these upgrades.
The vehicle customization menu can be accessed from any of the associates icons on your map – Cassandra just happens to be the first one you recruit, and thus gives you early access to that menu.
Mafia III is now available on PS4, Xbox One, and PC.