This page of the Mafia Definitive Edition guide contains a walkthrough for The Crazy Horse side mission available in the Free Ride mode. You will find out where to find the phone in the Little Italy district and how to drive the Crazy Horse vehicle without hitting anything.
You can learn about this mission by finding Herbert Baskerville's letter in the Free Ride. The letter lies on the pool table at Salieri's bar.
Before you start this mission, set the driving model to standard. The mission is about driving a vehicle that is difficult to control.
It has information on where the mission will begin. It is a telephone booth located at the western end of the Little Italy district. As you approach the booth, you should hear the phone ringing. Pick up the phone and the game will show you the details of this challenge.
Your task is to drive Crazy Horse to Holbrook in less than 3 minutes and 30 seconds. The biggest problem in this challenge is that you have to completely avoid any collisions. Even a minor collision with another car or element of the environment will result in failure. However, you can repeat this challenge as many times as you want.
Crazy Horse is a difficult car to drive. Let go of the gas pedal whenever you turn, otherwise, you will have very big problems with it. Remember to always get Crazy Horse onto a straight stretch of road before pressing the gas pedal again.
Crazy Horse is a very fast car – make use of this whenever you are driving on a straight road. However, watch out for cars coming out of side streets – they are easy to hit. It's good to slow down a little before every intersection. You should also keep in mind the long braking time, especially if there's a wider turn to make.
You should be able to reach your destination with no problems.
As a reward, you unlock the Crazy Horse vehicle. From now on, you can take it from any garage on the map. The game also allows you to change the color of the vehicle's interior.