From Halopedia, the Halo wiki
The Fossa was one of the most common sedans used on Andesia. It was common to see them on the streets of both Noctus and Promesa. In Noctus, the Fossa was also used by taxi companies. The Fossa was also used on Earth, more specifically the city of London.
The Fossa appears as a static object on the Halo 5: Guardians maps Urban, Battle of Noctus, Plaza and Overgrowth. It can also be placed as a Forge Object itself (with recoloring options) or it can be seen on a billboard advertising it.
List of appearances