Made a video of distortion at different focal length when shooting car pictures (or any other pictures, Portrait too)
If your car pic is terrible, this could be one of the reasons.
Very noticeable distortion at <14mm(or what else gopro is using, gopro website says 14, but it is wider than my iPad Pro 14mm lens), 14,24,28,35.
A bit at 50,75. pretty good after 120mm.