Andrew's racing career started after the turn of the century in a gravity powered Soap Box Derby car. In 2004, Andrew broke out of his shell and won the National Derby Rallies Stock Car National Championship. That same year he would race his way into the historical All-American Soap Box Derby National Race in Akron Ohio. The 2005 season would see Andrew once again race his way to Akron, but he would also start the fast pace action of dirt late model racing. Andrew would race his GM Crate Engine powered machine to a 7th place points finish at the I-80 Speedway. The 2006 season Kosiski would step up to the very competitive Grand National Late Model class at I-80. Andrew would only have 2 top 10 finishes in 16 starts, however a third place feature finish and a heat race win highlighted the season.
The 2007 season was unforgetable for the young Kosiski. Opening night at I-80 Speedway, Andrew would race from the third starting position to victory, his first career win. Andrew would also win the I-80 Speedway Race Of Champions, competing against some of the best drivers in the midwest. When the final checkered flag fell on the season, Andrew ended with 3 wins, 13 top fives, and 24 top tens.
The 2008 season saw Andrew take his first shot at a NASCAR series title. Finishing third in points at Junction Motor Speedway and sixth in points at I-80 Speedway, Andrew took 4th in the final Nebraska State standings and 100th in the NASCAR National Standings.
The 2009 season saw the 2x once again chase for the NASCAR Whelen All-American Series Nebraska State Championship. Andrew would finish 5th in the final standings for the state of Nebraska, and end up 18th in the final NWAAS National standings. Kosiski would finish 3rd in the final points standings at I-80 Speedway and 5th in the final run down at Junction Motor Speedway.
The 2010 season was a challenge for Andrew and the 2x team. With stepping up to the touring MLRA series and racing as many races in the NASCAR Whelen All-American Series as possible, the 2x experienced the most difficult season to date. Destroying both the primary weekly car in May and the MLRA touring car in August, the final standings reflected the difficulty of the season. Andrew would finish 7th in the state and 75th in the nation. The season would end on a high note, with Andrew picking up the victory at the McCool 100 at Junction Motor Speedway.
The 2011 season once again saw the 2x chasing after the NASCAR Whelen All-American Series Nebraska State Championship. Running both I-80 Speedway and Junction Motor Speedway weekly, Andrew would lead the State standings for many weeks during the summer months. With 3 wins, 15 top 5's and 26 top 10's in 29 starts, Kosiski would end the 2011 season 2nd in Nebraska State points and 16th overall in the National Standings, both career bests.
