Fixing device for together Establish two components, in particular one motor vehicle, with at least one locking element, that on one first component can be fixed or set is that across a Joining direction at least limited elastic bendable is that on a first component facing away free end at least across to joining direction operable Actuating portion and which is arranged between the actuating portion and the first Component at least one across to joining direction Recess and with at least one Recording unit which is connected to a second component definable or determines is at least one across to joining direction Locking lug on which the locking element Joining in joining direction sliding along and across or oblique to joining direction deflectable and which is in the recess of the locking element in a joined End position of the locking element rear grip with respect to the joining direction forming arrangeable is, and at least one of auflen accessible, across or oblique to joining direction Opening through which the actuating portion of the locking element at least in the joined end position of auflen accessible is, wherein the receiving unit is at least a across or oblique to joining direction extended Guide means which opens into the opening and through which a Tool along one unlocking direction is to release the locking element from the rear grip with the locking lug solve, through this characterized by a) the guide means at least one dome-like Survey includes, in which a Guide shaft and from outside accessible and which opens into the recess, and/ or b) the guide means on the side facing away from the guide shaft outer Surface a Fasteners for a component of the motor vehicle, in particular a decoupled in an elastomer air filter, forms. in particular one motor vehicle, with at least one locking element, that on one first component can be fixed or set is that across a Joining direction at least limited elastic bendable is that on a first component facing away free end at least across to joining direction operable Actuating portion and which is arranged between the actuating portion and the first Component at least one across to joining direction Recess and with at least one Recording unit which is connected to a second component definable or determines is at least one across to joining direction Locking lug on which the locking element Joining in joining direction sliding along and across or oblique to joining direction deflectable and which is in the recess of the locking element in a joined End position of the locking element rear grip with respect to the joining direction forming arrangeable is, and at least one of auflen accessible, across or oblique to joining direction Opening through which the actuating portion of the locking element at least in the joined end position of auflen accessible is, wherein the receiving unit is at least a across or oblique to joining direction extended Guide means which opens into the opening and through which a Tool along one unlocking direction is to release the locking element from the rear grip with the locking lug solve, through this characterized by a) the guide means at least one dome-like Survey includes, in which a Guide shaft and from outside accessible and which opens into the recess, and/ or b) the guide means on the side facing away from the guide shaft outer Surface a Fasteners for a component of the motor vehicle, in particular a decoupled in an elastomer air filter, forms. a) the guide means at least one dome-like Survey includes, in which a Guide shaft and from outside accessible and which opens into the recess, and/ or b) the guide means on the side facing away from the guide shaft outer Surface a Fasteners for a component of the motor vehicle, in particular a decoupled in an elastomer air filter, forms.