Didn't say any drivers did. However a little more background on the subject from a 2015 article, which shows NASCARs attempt to move away from the Confederate symbol, but was meeting resistance from the fans.
https://www.sbnation.com/nascar/2015/9/10/9299515/nascar-confederate-flag-darlington-south-carolina
NASCAR’s Confederate flag conundrum
[...]
And the "throwback" theme extended beyond what was happening on the track.
Throughout Darlington's infield and the camping grounds surrounding the track located in a sleepy town of almost 6,300,
there persisted the inescapable sight of a red flag with blue bars and white stars.
The Confederate flag and NASCAR have long been intertwined, the roots of each extending to the Deep South with some regarding both as Southern institutions. For decades the stars and bars were omnipresent at NASCAR races. Darlington's used to label its spring event the "Rebel 400," featured the flag prominently on programs and other advertisements and played "Dixie" during pre-race ceremonies.
Over the years, though, the sanctioning body has distanced itself greatly from the Confederate flag. This summer, following the shooting deaths of nine African-Americans at the hands of a white supremacist inside a Charleston, S.C. church -- two hours south of Darlington -- NASCAR CEO and chairman Brian France called it an "offensive symbol" and said, "we will go as far as we can to eliminate the presence of that flag."
NASCAR attempted to eradicate the flag from the speedway's grounds through a program where fans would turn in a Confederate flag and receive an American one in return. Except despite NASCAR's effort, the flag was quite conspicuous throughout the Darlington weekend. From flags to t-shirts, hats to can coolers, tattoos to pants it was impossible not to turn your head and see the symbol being displayed in some fashion.
At one flag exchange point there were no takers as of Sunday morning and a box of American flags sat untouched. Two security guards were clueless such a swap existed, while another dismissed the idea.
"No one in this crowd is going to give up their Confederate flag for an America one," the guard said. "They already own an American flag. Plus, they think by handing over the Confederate flag would be a form of surrendering in their mind."
Because either NBC didn't want to show a national television audience an event where the controversial flag was being displayed so freely, or event organizers wanted to give spotters a clearer view of the speedway (attendees say both reasons were cited by security, though neither could be confirmed as a Darlington spokesman declined comment), security personnel instructed patrons to take down their flags whenever cars were on the track.