A car is a beautiful thing right up until it breaks. The engine turns over, the paint gleams, and then one day a part fails, a specialist gets called in, and the beautiful thing has quietly become an expensive, ongoing negotiation that won’t let go easily. Muscle cars carry that risk more than most. Low production numbers, discontinued parts suppliers, and engineering pushed right to the edge of what a factory assembly line could reasonably handle all combine into a specific kind of ownership experience: gorgeous on a good day, and financially punishing the moment something fails on a bad one. Decades of scarcity have only made that worse, since a part that was merely expensive when the car was new can be nearly impossible to source at all once the original supplier has been out of business for forty years. Six legends below earned their reputations and their repair bills in roughly equal measure.