A lock is provided for a door of a motor vehicle. The lock includes a closing mechanism designed for coupling with a lock striker along a direction of relative coupling. The closing mechanism includes a supporting body having a housing seat for receiving an engagement portion of the lock striker. An elastically compliant buffer delimits the housing seat at least in the aforesaid direction of relative coupling in order to define a damped arrest of the engagement portion of the lock striker. The buffer is coated on its surface, in an area of interaction with the engagement portion of the lock striker by a rigid protective shield. The shield is fixedly secured to the buffer.