Continuity mistake: Takumi and Shingo both have their right hands duct taped to the steering wheel, as per the rules of the Gum Tape Deathmatch. During one shot of the race, Tak's hand is no longer taped and resting casually on top of the steering wheel as opposed to the right side of it.
Continuity mistake: Kenta's S14 changes color during his race with Takumi. Most notably during the two transitions between traditional animation and CG. The cel drawings give the car an orange tone before switching to the CG's darker but on-model Super Clear Red paintjob.