The plane flew over him just after he passed Jim Rennie’s Used Cars, a place for which Barbie had no love. Not that he’d bought a lemon there (he hadn’t owned a car in over a year, had sold the last one in Punta Gorda, Florida). It was just that Jim Rennie Jr. had been one of the fellows that night in Dipper’s parking lot. A frat boy with something to prove, and what he could not prove alone he would prove as part of a group. That was the way the Jim Juniors of the world did business, in Barbie’s experience.
Question: What does 'the JIM JUNIORS of the world' refer to?