Cox Wins Summer Thunder Series Feature at Cottage Grove Cottage Grove Speedway, Summer Thunder Series Justyn Cox. (Photo Courtesy of Tina Gargurevich) COTTAGE GROVE, Or. (August 4, 2017) — Justyn Cox won the Summer Thunder Series feature Friday night at Cottage Grove Speedway. Jason Solwold, Logan Forler, Chase Goetz, and Kyle Miller rounded out the top five. No related stories.