One thing leads to another.

Funny how perfectly that simple sentence describes so many car enthusiasts' lives. Greg Nelsen caught the bug as a teenager. His first Mopar led to many others — acquisitions and experiences that have come to define his life.

When he was in high school, Nelsen wanted a muscle car — specifically, a Dodge Charger or a Plymouth 'Cuda. Yet their prices were just out of reach. In the mid-1980s, he got hurt in a serious car accident. It reminded him that life is short. After he pulled through, he decided it was time. He responded to a Wisconsin ad and drove there to look at a red '70 Charger with a 440 cubic-inch V-8 and a honkin' Hurst pistol-grip shifter. He knew a little about auto bodies, but was no Mopar expert. Still, he made his wife stand around for a long time while he climbed around the car checking it out. He even convinced the patient-but-puzzled owner to let him drive it to Minnesota, where his friend Dan Nord at Downtown Jaguar threw it on a lift and proclaimed it sound.

"That car was outrageous," he says. "Going down the road, it felt like an earthquake." As soon as he brought it home, everyone who saw it wanted it. They wouldn't leave him alone. He had paid $6,000 for it. When someone offered him $10,000, he let it go and bought a purple one. Then people wanted that car. One thing led to another. Local enthusiast, Richard Burton, sold him a Superbird and led him deeper into Mopars. Every Mopar Nelsen bought drew car fans out of the woodwork. They wanted his car, they wanted one like it, they wanted any number of Mopar muscle cars and they wanted him to help them get those cars. His collection grew rapidly and so did his circle of Mopar-loving friends. He learned the cars, he learned where to find them and he "horse- traded" around to build his own collection.

It wasn't long before his driveway was filled with Mopars, maybe 10 cars. His tuck-under garage also had cars and parts in it. He and his wife had to park in the street and walk past his car assortment to get to and from the house. Only a severe storm pushed him to a new arrangement. He was sitting in his kitchen listening to the wind howl when car covers started blowing by the window. Driveway storage was history.

Nelsen sold a Hemi 'Cuda and bought a hobby farm. Meanwhile, his "disease" as he calls it, was producing an accretion of cars and their market value was climbing rapidly. Unlike real ailments, Mopar disease was an affliction he was thankful for, especially since his stable was large before the prices went stratospheric. He built a storage building on the hobby farm and got his treasures inside, naming the property "Mopar Ponderosa." Today, Nelsen keeps roughly 15 to 20 cars, which he maintains with the help of his long- term friend, Troy Martinson. Nelsen likes to own them much more than sell them, but he'll let some go for the right deal. He prefers to horse-trade rather than sell outright, because having cool cars is more fun than having the money. Most important, he likes to use the cars. Among his daily drivers are a Plymouth 'Cuda and Superbird. During the summer he uses them everyday. He'll drive the Superbird, which he calls "one of the most obnoxious, bodacious, wildest muscle cars ever made," to the hardware store with his dog in it. Half the people who see the car go nuts and half just gape.

Once he pulled up next to a "tuner," and the young man at the wheel commented on the Superbird's outrageous spoiler. "Where'd you get it?" he asked. "Plymouth," Nelsen answered. "How much?" the kid said. "Five thousand." He drove off. Not quite in the young driver's budget — but then, the part had been on back order since before he was born.

Nelsen feels both satisfied and lucky to have his assortment of spectacular streetfighters. "Even if the market falls and their value goes down, I'll still have a bunch of cool cars," he reflects. "A guy with his money in the stock market just has pieces of paper. How much fun is that?" Indeed.