Both NASCAR series will end their three-week western swing in California this weekend with races at Auto Club Speedway that will be heard live on WEBO. Through the first four weeks, both the Xfinity and Monster Energy Cup Series have yet to see a repeat winner. That could change this weekend. Austin Dillon is the defending champion of tomorrow’s Xfinity Series race. Motor Racing Network coverage will begin at 3:30pm. The Monster Energy Cup will race the Auto Club 400 on Sunday. MRN coverage will start at 2:30pm. California native Jimmie Johnson won last year’s race.
