NASCAR XFINITY DFS: U.S. Cellular 250 DraftKings Preview July 26, 2018 Brian Polking DFS - NASCAR, DFS - ScoutDFS Shanna Lockwood-USA TODAY Sports The XFINITY Series visits Iowa Speedway this weekend, and NASCAR expert Brian Polking gets you ready to cash in at DraftKings with his DFS Preview for the U.S. Cellular 250.To access this post, you must purchase DFS - NASCAR, SFS - DFS - Three Month Free Trial, DFS - One Month All-Access Free Trial, DFS - One Month Free (no credit card required), SFS - DFS - Three Months Free (no credit card required) or DFS - CORE Sports (NFL, MLB, NBA, NHL). Christopher BellDraftKings NASCARIowa SpeedwayJustin AllgaierNASCAR DFSU.S. Cellular 250XFINITY Series