Think airbags (especially side-curtain), ABS, and lots of other safety stuff can be more trouble than it's worth.

These devices are not foolproof, and they add both to the initial cost and cost of repair.

As a car ages, always the chance that something can go wrong. Aren't airbags supposed to be replaced once a car reaches a certain age?

All for safety and such simple changes as seatbelts and radial tires. But past a certain point we're talking mandated gimmicks that create a false sense of security.