Ride along side his car and take him out with a silenced pistol.

From Create Your Own Story

You speed up so Mario can get a shot at Donnu. It's a hard maneuver but you manage to get alongside of him and right as he is about to tell you to fuck off Mario blows his brains all over the passenger seat. No one sees your car and Donnu's car just crashes into a telephone pole. The police only find the bullet entry, not the bullet itself.

Mission Successful!: Target assassinated, No witnesses, 2,500 earned each.

Target: DEAD- killed by a a shot to the head.

• Luigi: Alive
• Mario: Alive- assassinated Donnu.
• 3rd Partner: N/A
• 4th Partner: N/A

Donnu is dead and 4H foods soon follows. Without its financial genius and excellent marketing, 4H is reduced to a simple stand manufacturer and Lipton is able to corner the Food Stall market. You can go back and move onto the next target on your list or see other ways this could have turned out.