Mucho bad.Every time you give the engine gas, it torques upward. If it is not mounted securely, it pulls all the belts, brackets, pumps, etc. with it and it's only a matter of time before things begin to break loose.I don't know what you mean by the speedometer question and I have never heard of any car being governed by the factory but if you are talking about 118-120 MPH in a Honda Civic, maybe they should!Good Luck