The invention relates to a connecting device (1) for connecting a first part having the connecting device (1) to a second part comprising a latching part (3) with a base (6) on which at least one side wall (8) is disposed and which is configured for engaging receipt of a mating part disposed on the second part. A connecting element (2) made of a weldable polymer is disposed on the base (6) and/or on the at least one side wall (8).