The present disclosure relates to an off-road vehicle having different features such as an engine assembly, a frame having a frame structure, and a rear mount assembly facilitating easy installation of the engine assembly, and a method of installing the engine assembly. Embodiments of the present disclosure also describe a removable frame member facilitating the installation of the engine assembly from a seating area into a rearward portion of the vehicle. The removable frame member is positioned at least partially forward of the installed engine assembly and in a lateral direction of the vehicle. The frame structure and the rear mount assembly provide more efficient assembly of the engine and transmission assembly into a tight space envelope.