While maneuvering in a parking garage and switching between reverse and forward, the engine suddenly and unprompted revved excessively, sounding as though the accelerator pedal was floored. The vehicle forcefully lunged forward against braking pressure into a cement wall, causing front-end damage to the vehicle. Cruise control was completely disabled and no check engine light or warning indicators illuminated on the dashboard. At no time did I feel like I had control over the car. I sustained some contusions. No one was in the vicinity at the time; however, other cars and/or people could have been struck. The vehicle has yet to be examined by anyone although I am in the process of arranging for an autobody repair shop. Prior to this, the car was in its usual state of health without any issues.