Xiao Lie and Xiao Hao are fans of model 4WD cars. At a young age, they have learned a lot about model 4WD cars. With the help of Dr. Tsuchiya, a model 4WD car expert, their 4WD cars have won many awards in various competitions. However, recently, some extremely destructive racing cars suddenly appeared. They not only have an absolute speed advantage, but also can crush the opponent's 4WD cars! It turns out that this is a new generation of 4WD cars developed by the evil Dr. Da Shen. In order to defend their honor and defeat Dr. Da Shen's team, Xiao Lie and Xiao Hao began to completely transform their 4WD cars!