Grand Theft Auto: Vice City - The Definitive Edition

This solution works for both the "Courier" trophy and the transport mission: Pizza Boy (complete level 10).
To complete all 10 levels, you will need to deliver a total of 55 pizzas, refilling the pizza box at least 14 times at the takeout window, depending on your route(s).
Completing all 10 levels will take about 30-45 minutes. Completing level 10 is one of the requirements for
100% completion.
Once completed with a vehicle (full level 10), it will add 1% to your overall game completion percentage. In-game reward for completing: Your maximum health is increased to 150.