INDIANAPOLIS – Dale Earnhardt Jr. was gone, and so were they.

Hundreds of fans poured out of the Indianapolis Motor Speedway grandstands Sunday, barely halfway through the 2017 Brickyard 400, when Earnhardt’s No. 88 Chevrolet wheezed into pit road, its radiator smoking, its day done.

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Earnhardt climbed out of his car under a sign for Gasoline Alley, drawing the loudest applause of the day, and disappeared from view. Fans in blue Dale Earnhardt Jr. T-shirts followed him out, walking to the infield parking lots, triggering a bizarre exodus of cars out of IMS even as the Brickyard 400 was still going.

Larryssa Mercer of Brownsburg was wearing a faded blue Dale Earnhardt Jr. T-shirt and a devastated look as she walked out of the grandstands. Not sure that I was seeing what I was seeing, I had to ask her:

Are you leaving because Dale’s out? Is that why everyone’s going?

“Absolutely,” said Mercer, 48. “Well, I don’t know about everyone else, but I came here to watch Dale race. If he’s not racing anymore, I’m not watching anymore.”

Larryssa didn’t grow up a NASCAR fan. Her husband was, and he liked Dale Jr., so Larryssa started paying attention to this sport, and to that driver. And she fell in love. A few years ago, Larryssa divorced her husband.

She kept Dale Jr.

“I love how he’s always so positive,” Larryssa was telling me. “Win or lose, he’s always got a smile on his face.”

Lose or lose, these days. Dale Jr. hasn’t won since 2015, and has barely contended in 20 starts this year. He wasn’t going to win the 2017 Brickyard 400, but his fans didn’t come to IMS to watch him win. They came to see him race. And for many, they came to say goodbye.

Dale Jr. announced in April that this season, his 19th, would be his final as a full-time driver. His retirement has seeds dating to 2012, when he suffered two concussions in six weeks. Less than three months after news broke in March 2016 that Dale was donating his brain to concussion researchers, he suffered another concussion at Michigan that ultimately sidelined him for the final 12 races of 2016 and triggered his retirement after this season.

And so while Kasey Kahne won the 2017 Brickyard 400 even as Kyle Busch dominated most of the race — until crashing with Martin Truex on a restart on Lap 112 — Dale Jr. dominated it in every other way, the same way he has dominated the 2017 Cup Series.

Drivers like this, this beloved, they don’t come along very often. Given the popularity precipice facing NASCAR, which is teetering on the abyss of irrelevance, a driver this popular might not come along again. Yes, I’m saying: ever.

Look, if you know much about NASCAR, you already know that. While the country’s top stock car circuit has always had one or two dominant personalities on the track, those dominant personalities — think Jeff Gordon; think Tony Stewart; think, even, Dale Earnhardt Sr. — tend to generate as much hate as love.

Not Junior. Not Little E. For him it’s all love, a testament to his ability to drive a car, sell Budweiser and act like the regular country dude he seems to be, not the multi-million-dollar tycoon he was born to be. The driving ability has diminished — he has zero wins and one top-five finish in 20 starts this season, compared to 26 wins and 143 top fives from 1999-2015 — but not the popularity.

And Earnhardt’s ability to move product remains unmatched. During the thunderstorm that delayed Sunday’s race for almost two hours, business was booming at Earnhardt’s memorabilia trailer. Nearby, the memorabilia trailer for Kyle Busch is making do with one clerk. Kevin Harvick’s trailer has two clerks, Jimmie Johnson’s three.

Dale Jr. has nine clerks.

Dale Jr. has two trailers.

Golf balls, Ping-Pong balls, gray footies with “Dale Jr.” sewn in hot pink, this trailer — sorry, these trailers — sell some really silly stuff. I ask a clerk if they have any Dale Jr. onesies, and she asks me which size and points to a rack that has onesies for babies at 6 months, 12 months and 18 months.

Sorry, I tell her. I was just trying to name the silliest thing I could think of to put the Dale Jr. name on.

One cash register over, a male clerk has the answer for me:

“Try one of these Dale Calls,” he says.

A Dale Call, it turns out, is like a duck call — only, instead of summoning the sound of a duck at mating season, it summons the sound of Earnhardt’s No. 88 engine.

For $29.99.

“These are very popular,” the clerk tells me.

And now this popular driver, arguably the most popular driver in NASCAR history, is leaving — with no heir to take his place, and with what happened Sunday demonstrating that support for NASCAR and Dale Jr. can be mutually exclusive.

The horde of Dale Jr. fans heading for the infield while the Brickyard 400 roared around them included a man in a Dale Jr. T-shirt and Dale Jr. ball cap, holding a bag of Dale Jr. memorabilia. He’s from Shelbyville, this fan, and his name is Jason. He told me his last name but asked me not to use it — “Call me Jason W.,” he said — because of some family drama.

Jason grew up a fan of Dale Earnhardt Sr., but he kept an eye on Dale Jr. and decided it was cosmic when Dale Jr. won his first race — the 2000 DirecTV 500 at Texas Motor Speedway — on April 2.

“That’s my birthday!” Jason’s telling me. “And I can prove it.”

Now he’s fishing out his driver’s license, and sure enough, Jason was born on April 2.

But you’re a NASCAR fan, I tell him. Right?

Jason nods.

Why are you leaving right now?

“Well, I could hang around and see who won,” he says, “but …”

His voice trails off as he looks at me and shrugs, delivering the rest of his message clearly enough.

Back to the media center I go. My path leads me past Earnhardt’s garage on Gasoline Alley, where I spot Larryssa Mercer leaning against the chain-link fence, trying to get one last glimpse of Dale Jr.

I don’t have the heart to tell her:

Dale Jr. is gone. And he’s not coming back.

Find IndyStar columnist Gregg Doyel on Twitter at @GreggDoyelStar or at facebook.com/gregg.doyel.