Tires

The government need rubber, which was in high demand, for the war effort. Contrary to many other items that were rationed, sales of rubber were essentially ceased. This indicated that tires were no longer being made. Those in need of new tires were in a dangerous situation. Great if you had a spare. You wouldn't be able to find a new one if you didn't.

In addition to extending the life of gasoline supplies, the new 35 mph speed limits were also implemented to conserve rubber at home. The rubber was required for supplies and military vehicles used abroad. That indicates that a black market for individuals in need could be established in the early stages of the war at home. Keep in mind that this was back when it was difficult to create synthetic rubber. Rubber trees couldn't be grown in America, and imports from abroad had to stop, thus America required access to them.

The demand for rubber was so high that when people returned from work for the day, their car's tires were gone. Black market tires could be purchased for as much as $50 per. Even though it may not seem outrageous in today's prices, a brand-new tire during the war cost five times as much as it does today.