The number of prototypes General Motors destroys during development of any new car—a dozen or so—is negligible compared to the many thousands it hopes to sell. Not so for specialty-car makers, who can see up to 25 percent of their annual output smashed to smithereens in the process of development. It’s no wonder these companies think twice before performing the tests required to sell a new vehicle in the U.S. Here are a select few of those tests:

Emissions: At least this one doesn’t damage the cars, which are mounted on a dynamometer, or “rolling road.” Over a 41-minute period, the U.S. Environmental Protection Agency runs a single car through a series of tests including cold start, acceleration, braking, shutoff, and restart. Exhaust is collected in a huge bag and analyzed for hydrocarbons, nitrous oxide, and carbon monoxide. Cars that exceed the limit for any substance may not legally be sold.

Roof strength: To simulate a rollover, a 30-by-72-inch steel plate is pressed against the roof with a force equivalent to 1.5 times the vehicle’s weight. Safety advocates say the requirement that a roof may buckle five inches or less, which hasn’t changed since December 1971, is woefully lax. And the cars used in testing still end up with crushed tops.

Side impact: The National Highway Traffic Safety Administration places dummies in the driver’s seat and left backseat of a vehicle, with seat belts fastened. A barrier is then slammed into the car’s side at 38.5 m.p.h., while instruments measure the force sustained by the dummies. The results are rated from one star (worst) to five stars (best). As with any car in a major collision, the test vehicles have to be scrapped.