Buying a used car can be a smart financial move, but it’s not without risks. While many pre-owned vehicles offer years of dependable service, some are notorious for hidden issues that can drain your wallet and patience. Experienced mechanics often warn buyers to steer clear of specific makes and models, based on patterns of mechanical failures, costly repairs, or serious safety concerns. Understanding which cars are most frequently flagged by the pros can help you avoid regret—and expensive surprises—down the road.