Sidewinder (サイドワインダー Saidowaindā) is a highly skilled team that organized the "4 lines of defense", who make their debut in Fifth Stage. Their home course is the Tsubaki Line, but the nearby Toyo Turnpike may be a part of their home territory (Ryosuke's battle with Rin Hojo was raced there). They are considered the "fourth line" or the last team in Kanagawa that Project D competes with. In the storyline, this team attempts to analyze Project D's weaknesses throughout Fifth Stage before their initial battles with them. Eiji Kubo acts as the team's chief mechanic and strategist, and does not actively participate in battles. They collect information by watching Project D during their practices and races, which is done by timing them through data collection teams and having Kubo and Go Hojo spectate together during the races leading up to their battle against Project D.
|Go Hojo||Honda NSX (NA1)||Uphill|
|Shinji Inui||Toyota Sprinter Trueno GT-APEX 2door (AE86)||Downhill|
|Rin Hojo||Nissan Skyline GT-R (BNR32)||Downhill|