A suspicious-looking man drove up to the border, where he was greeted by a sentry. When the guard looked in the trunk, he was surprised to find six sacks bulging at the seams.
"What's in here?" he asked.
"Dirt," the driver replied.
"Take them out," the guard instructed. "I want to check them."
Obliging, the man removed the bags, and sure enough, each one contained nothing but dirt. Reluctantly, the guard let him go.
A week later, the man returned. Once again, the sentry inspected the truck.
"What's in the bags this time?" he asked.
"Dirt, more dirt," said the man.
Not believing him, the guard checked the sacks and, once again, found nothing but soil.
This same scenario repeated every week for six months. It finally became so frustrating for the guard that he quit and became a bartender.
Then one night, the suspicious-looking fellow happened to stop by for a drink. The former guard hurried over to him and said, "Listen, pal, drinks are on the house tonight if you'll do me a favor: Just tell me what the hell you were smuggling all that time."
Grinning broadly, the man leaned close to the bartender's ear and whispered, "Cars."