SPARTA, KY—Fans attending the Sprint Cup Series’ past four races have witnessed a strange phenomenon: a black family who drives a motor home onto the racetrack’s infield and watches every event of the weekend. “Frankly, they freak me out. They show up with the same radios we use to listen to drivers talk to their crews. They all wear T-shirts with drivers on them. They’re black. I’ve never seen anything like it,” race fan Darrel Swinea told reporters Saturday during the Quaker State 400. “I’d go ask what they’re up to, but, well, uh, you know.” Around lap 56 of the race, the father of the black family turned to the crowd staring at him and asked if anyone wanted some of the beer or venison sausage from his cooler, causing spooked fans to immediately run out of the grandstand and into the parking lot.