Dollar signed with DGR-Crosley in October 2018 to compete part-time in the NASCAR K&N Pro Series East and the CARS Late Model Stock Tour. In his debut K&N East race at New Smyrna, he qualified second, led 48 laps, and finished ninth. He ran nearly the full season and finished ninth in the championship standings, with all but one result being a top-ten finish.
Dollar also made two ARCA Menards Series appearances for DGR-Crosley in 2019, driving their No. 4 Toyota at Gateway and Kansas, finishing sixth and seventh respectively. An additional K&N Pro Series West start at Phoenix came as preparation for an upcoming ARCA race at the track.
In December 2019, Dollar was announced as the full-time ARCA driver for Venturini Motorsports in 2020, taking over the No. 15 Toyota from Christian Eckes, who graduated to the Truck Series. On June 20, 2020, in only his fifth ARCA start, Dollar claimed his first series win at Talladega Superspeedway. He ended the season fourth in the championship and runner-up in the Rookie of the Year standings.
In 2021, Dollar returned to Venturini on a reduced schedule of eleven ARCA starts, splitting the No. 15 with Gracie Trotter. He also received an additional start each in the ARCA East and ARCA West series.
In 2022, Kyle Busch Motorsports absorbed Joe Gibbs Racing's ARCA operations and signed Dollar to four races in the No. 18 Toyota.
On January 28, 2021, Dollar was announced for a part-time Truck Series schedule in the No. 51 for Kyle Busch Motorsports, beginning with the Daytona season opener. He competed in eight races under the Toyota development umbrella.
Dollar's career became associated with on-track incidents that drew public attention. At the 2021 ARCA race at Michigan, a collision with Thad Moffitt triggered a retaliatory crash that injured a third driver. At the 2022 Kansas ARCA race, Dollar was battling for the lead with Corey Heim when he spun out, crashing both cars. In the aftermath, former team owner Billy Venturini delivered a pointed public criticism in a televised interview, stating that Dollar was a great person but not suited for racing. Dollar ran one more ARCA event at Charlotte in 2022, finishing 24th after another crash, and made no further starts. He quietly stepped away from professional racing to pursue his college education.
Dollar's career arc reflected the compressed timelines of modern NASCAR development programs — a Talladega win in just five ARCA starts, a Toyota truck deal, a Xfinity Series debut — but also the fragility of sponsorship-dependent pathways at the developmental level. His departure at 21 illustrated how quickly the window can close in professional stock car racing.