A muscle car is a car made from a sedan or luxury car and also made from the factory specifically for performance examply Mustang: pony car Why: there is no four door or toned down version of the car ever made before it same with cameros and challengers. Now for example the Charger: muscle car because it was made to be a bad *** car and also is made from the more toned down plymouth sattelite same with the GTO being made for performance from the Lemans/Tempest and also with the Chevelle being made from the Malibu. so the Monte carlo is not really a muscle car but in the older years it is classified as a personal luxury coupe and the newer monte carlos are now concidered as a full sized coupe. But if a car show limited their entries to only textbook musclecars then their would be a very bland show of seven or eight awsome cars over and over again lol