This is the answer and not les because even spanish speakers use that form when they speak is not the correct one according to the grammar rules of the language. Besides the action that is indicated here is made by the third person of singular so the only option that goes according to grammar and person is le
El joven tiene su coche en __.el tallerEl coche necesita __.pinturaEl mecánico está __ cuando llega el joven.alegreEl mecánico pintó __ en el coche.llamasAl ver su coche el joven está __.sorprendido