Every fall, the new-car season brings fresh models and industrywide optimism, but it’s also the time when automakers are forced to acknowledge what’s not selling as discontinued models disappear from company Web sites and dealership lots. With few exceptions, a canceled car is a slow-selling car.

Some vehicles fail to meet expectations from the very start. Many more lose their relevance over time. It’s a rare automobile that is introduced with a firm expiration date in mind.

While models like the BMW M3 and the Volkswagen Golf R are skipping 2014 because of redesigns, the vehicles presented here are truly dead. Don’t expect to see new models wearing these badges anytime soon, if ever:

ACURA ZDX The genre-bending ZDX combined the ride height of an S.U.V., the roofline of a coupe and the four doors of a sedan. From the driver’s seat it was as well-sorted as the more conventional MDX, but the ZDX’s styling left buyers confused enough that Acura never met its modest goal of 5,000 sales a year.