And then came the 18-wheeler that carried O'Neal to his public arrival in Miami, as he happily fired a squirt gun at throngs of screaming fans.
"We had a vision to be a championship team," Wade told The Associated Press on Wednesday, "but it wasn't for real for real until Big Fella came and pulled up on that truck."
A grand celebration was had on that day in July 2004. The franchise's first of three NBA championships followed two years later, and the Heat will give O'Neal their version of an ultimate thank you on Thursday night when they raise his No. 32 to the rafters.
"I said, 'I promise I'm going to bring a championship here,'" O'Neal said. "And we did."
Fittingly, the Heat will fete O'Neal at halftime of a game against the Los Angeles Lakers -- who also have retired his number.
"He changed the direction of our team," Heat president Pat Riley said. "He brought an absolute legitimacy to our franchise. And when we won the championship, I think it sort of took us over the top. He deserves to be honored by having his number hanging from the rafters. It's not just out of respect. It's because of what he did for us."
The NBA is permitting a longer-than-usual halftime for the ceremony, in which Riley and O'Neal will be among the speakers. O'Neal won his first three titles with the Lakers, then got his fourth in Miami to make good on the promise he made when he stepped out of that truck.
And, in a nod to that infamous arrival, the Heat will have an 18-wheeler bearing the "Diesel Power" artwork that greeted him 12 years ago at the arena.
"Big Fella in Miami changed everything," said Wade, who's now with the Chicago Bulls but will one day have his jersey hanging next to O'Neal's in Miami. "Changed everything for everyone."
O'Neal appeared in 205 regular-season games over parts of four seasons with Miami, averaging 19.6 points and 9.1 rebounds. But his impact stretched well beyond stats; he helped turn Heat games into events, and did so while not impeding Wade's rapid rise to superstardom.
There were some well-documented troubles along the way. When Stan Van Gundy stepped down as coach in 2005, part of that decision was believed to be related to his relationship with O'Neal. And when the Heat traded him to Phoenix in 2008, O'Neal blasted Miami's personnel -- including guard Chris Quinn -- along with the team's medical and athletic training staffs.
Quinn is now an assistant coach with the Heat. And O'Neal's jersey banner will sway next to one for Ron Culp, a revered figure in Heat history and the team's athletic trainer from 1988 through 2008.
"It was not personal," Riley said. "Shaq was impeccable with his word. He came down here and said, 'We're gonna win a title, Coach.' And we won a title. ... No hard feelings, at all. I'm an Irishman and I forgive."
So with that, all is forgotten, all is forgiven.
"Next to Dwyane, I'd have to say he's probably the best teammate I ever had," Heat captain Udonis Haslem said. "Just showing us how this NBA life works, how you can have fun and enjoy it but stay out of trouble and win games. He put so much confidence in his teammates. He really was the great Shaquille O'Neal."
Haslem was a second-year undrafted player when O'Neal arrived, and remembers hearing that an undersized power forward like himself wasn't the sort that would work well with a still-dominant center.
O'Neal let Haslem know right away to ignore such talk. Haslem wound up playing a huge role in Miami's 2006 NBA Finals victory, and is still so revered by O'Neal that he wants him to join in the ovations from the crowd on Thursday night.
"The first thing when I got with Big Fella, he said, 'I've been watching you, I like your work ethic and I can win with you,'" Haslem said. "A player like that has confidence in you, how could I ever question that?"