The hood is the single cosmetic part that could be a source of safety problems. There are two possible concerns.
In the absence of a crash
The first possible concern has nothing to do with performance in a crash. It has to do with whether a hood latch or attachment points could fail while driving and allow the hood to fly up suddenly, obscuring the driver's view. Consumer Reports has cited an unverified claim that an aftermarket hood failed in this manner and caused a crash.
A notable absence from the same article is acknowledgement that hoods from original-equipment manufacturers can, and do, have defective latches and/or attachment points that fail in the same manner. Auto manufacturers have conducted 47 safety-related recalls involving original-equipment hoods, mostly because of hood latches and attachment hardware. A total of 6,216,946 vehicles have been recalled. Many cases have involved hoods that flew up, causing some reported crashes.
"Such a large number of safety-related recalls of original-equipment hoods lends perspective to the unsubstantiated allegation in Consumer Reports that aftermarket hoods are somehow inferior," Institute president Brian O'Neill notes.
The quality of many aftermarket crash parts used for auto repairs, including car hoods, is evaluated by the Certified Automotive Parts Association (CAPA). "All hood latches and strikers are subject to additional testing," CAPA says, "to evaluate their dimensions, retention, and hardness of core and case." Other than hoods, the parts CAPA certifies aren't safety-related. This group doesn't certify parts that are subject to the requirements of federal motor vehicle safety standards.
The second possible concern relates to hood performance in crashes — whether they will buckle, as new-car hoods are designed to do, so a hood doesn't get driven back near the windshield. CAPA certifies hoods by ensuring that the same buckle points present in hoods from car companies also are present in the aftermarket hoods it approves.
"Hoods must buckle as they're supposed to, or else safety could be compromised," O'Neill says. "It's obviously not feasible to crash test every aftermarket hood. But in several tests in which original-equipment hoods have been replaced by aftermarket ones, the replacement hoods have performed exactly as they should. This is to be expected because the buckle points are built in."