Here is the full list of all 43 Mafia: Definitive Edition achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Completed the game on Classic difficulty
Collected 30 vehicles in the Garage
Performed a wheelie for 3 seconds
Found all Mystery Foxes
Found all Pulp Magazines
Completed the Collection
Found all copies of Gangsters Monthly
Found all 'Gangsters of the United States' cigarette cards
Found all of the hidden cars
Lockpicked 5 cars on the streets of Lost Heaven and environs
Found a hidden car
Completed the game on Easy, Medium, or Hard difficulty
Completed "The Death of Art"
Completed "Moonlighting"
Completed "Just For Relaxation"
Completed "Election Campaign"
Lost the cops after accruing a five star police chase
Collected 15 vehicles in the Garage
Completed "Crème de la Crème"
Completed "You Lucky ..."
Completed "Happy Birthday"
Resisted arrest by the Lost Heaven Police Department
Completed "Bon Appétit"
Completed "Great Deal"
Completed "Visiting Rich People"
Reached 50mph while driving the Bolt Ace
Completed "Omerta"
Paid a fine to the Lost Heaven Police Department
Completed "A Trip to the Country"
Completed "The Saint and the Sinner"
Completed "Better Get Used to It"
Completed "Sarah"
Completed "Fair Play"
Took Paulie to a Place of Disrepute
Won the race
Completed "Ordinary Routine"
Found a Mystery Fox
Found a copy of Gangsters Monthly
Completed "Molotov Party"
Found a Pulp Magazine
Found a 'Gangsters of the United States' cigarette card
Completed "Running Man"
Completed "An Offer You Can't Refuse"