A method for manufacturing first and second trim parts of a vehicle, the first trim part having a first thickness and the second trim part having a second thickness different from the first thickness. The method includes introducing the first trim part and the second trim part between a front and a back tool of the forming mold, the front tool having a front fixed part and a front movable insert movable with respect to the front fixed part along a main direction, the back tool having a back fixed part and a back movable insert movable with respect to the back fixed part along the main direction; and adjusting settings of the forming mold to different values for the first and second trim parts.