Jushavenfun: This appears to be one of the MPC passenger cars that are actually two pieces of plastic that snap together using the "cloudy" passenger windows as the retaining feature. The car actually comes apart at the roof-to-body split line.
Look carefully at the windows; you will see that one window in each row will have a thicker portion of plastic at the top of the window. There are four total that hold the roof to the body. Push in gently on each window to release it from the body. It is helpful to have something like a 3 X 5 card to insert between the window and the body to keep it released while you work the others. Once you have all four in the "release" position, lift the roof and cloudy window assembly out of the car body to access the innards.