This mod solidifies the interior of the bus and removes the collision on the doors, so Vito can walk through them. This was done by replacing the bus seen on the streets of Empire Bay, which had its interior collision removed after public transportation was cut to conserve memory, with the prison bus, which was not edited after the removal of public transportation.
Install: Open the zip file. Locate the folder in the PC. Open The “C:/Program Files (x86)/Steam/steamapps/common/Mafia II”. Change the PC folder here.
Credits: Draconio
File Details:1,1 MB / ZIP Download Mafia 2 – Ride The Bus Mod - Modsup.com
I followed the instructions, but this mod only replaces the Parry Bus with the Police Bus; it still is not rideable.