What do you think a Machmeter is? What is an equivalent piece of equipment on a car?

A machmeter is an instrument which provides an indication of the Mach Number, which is the ratio between the aircraft true air speed, and the local speed of sound.

Fender is the American English term for the part of an automobile, motorcycle or other vehicle ... The equivalent component of a bicycle or motorcycle, or the "cycle wing" style of wing fitted to vintage cars, or over. They either come with a vehicle as a standard equipment or are added afterwards as an aftermarket accessory.