Ma Da, a talented car repairman hidden in a repair shop in a village in the city. He has a unique skill: identifying faults by listening to sounds. Any slight abnormal noise from the engine is an accurate diagnostic report in his ears. With this skill and top-notch modification technology, he is well-known in the black market racing circle, but he never goes out to race cars himself, only willing to stay with the engine oil under the car.
Until a second-hand car he inspected for a client was found to be in a major accident. The client was seriously injured in the car accident, but the owner of the car dealership, Chen Deli, refused to admit his fault. Ma Da discovered that the owner of a second-hand car dealer was making huge profits by reselling damaged cars and accident cars, and there was a gray black market modification industry chain behind him.
In order to seek justice, and to blow up this black chain that harmed riders, Motor was forced to enter the illegal racing track late at night. He used a pile of scrap metal to modify a chariot, and relied on his unique skill of identifying positions by listening to sounds, from underground racing to black market gambling, from street competition to abandoned racetracks. The engine roars, and the sound is a declaration of challenge. A car mechanic needs to use a wrench and accelerator to pry into the underground racing shady scenes of the entire city.
