* Consult your owner's manual: This is the best resource for the precise location specific to your vehicle's engine.
* Look for a small sensor: It's usually a relatively small, cylindrical sensor with a wiring harness attached. It's often found near the throttle body, but not always directly on it.
* Use a repair manual or online diagrams: A Haynes or Chilton repair manual, or online resources like Ford forums dedicated to 1995 Mustangs, will have diagrams showing the sensor's location.
Searching online for "1995 Ford Mustang [your engine size] MAP sensor location" will likely yield images and diagrams to help you visually identify it.