Method for washing vehicles, in particular cars or the like, in combination with a washing machine comprising at least one portal on which at least one support group of at least one dispensing nozzle for at least one high-pressure washing fluid is mounted, a hydraulic circuit for feeding said fluid at a predetermined pressure being provided and said portal and/or said support group of said at least one nozzle being moved with respect to the vehicle along a path of said non-interference group with the shape of said vehicle and/or accessories associated with the same, said at least one nozzle on the said support group being supported in a position such that the propagation axis of the jet delivered by said nozzle is oriented against a facing surface of the vehicle and wherein the method provides for identifying a protruding element of the profile in lateral and/or front and/or rear projection of the vehicle and of the relative undercut area delimited by the same and temporary stopping of said support for said at least one nozzle in a vertically and/or horizontally position substantially aligned with said protruding element or with said undercut area and wherein the jet delivered by the nozzles is oriented incident against said undercut area and wherein scanning with at least one scanning member the lateral and/or front and/or rear profile of the vehicle and analysying in an analysing unit said profile obtained from said scan, said analysis unit being configured for the identification of the areas of said profile corresponding to protruding elements that form undercuts in the vehicle profile according to a lateral and/or front and/or rear projection of said vehicle, and which analysis unit controls, directly or indirectly, the positioning of the portal and/or of the support group of said at least one nozzle and/or the orientation of said at least one nozzle in a position vertically aligned with the area of said protruding element and/or with the area directly underlying the same and wherein the jet (s) of said at least one nozzle are oriented against the area that delimits said undercut, between the side of said protruding element and the wall band of the vehicle to which the said protruding element overlaps, wherein the hod provides for determining by the analysing unit the position of the undercut area thanks to a method which provides for the identification of a vertex of directional change of the line which defines the scanned profile of the vehicle and/or a jump in position of said line, in combination with a signal entered by a user relating to the indication of the presence of a protruding element of the profile and a relative undercut, said undercut area being defined on the basis of an average distance value with respect to said vertex or to said jump in position of said line of the scanned profile. a hydraulic circuit for feeding said fluid at a predetermined pressure being provided and said portal and/or said support group of said at least one nozzle being moved with respect to the vehicle along a path of said non-interference group with the shape of said vehicle and/or accessories associated with the same, said at least one nozzle on the said support group being supported in a position such that the propagation axis of the jet delivered by said nozzle is oriented against a facing surface of the vehicle and wherein the method provides for identifying a protruding element of the profile in lateral and/or front and/or rear projection of the vehicle and of the relative undercut area delimited by the same and temporary stopping of said support for said at least one nozzle in a vertically and/or horizontally position substantially aligned with said protruding element or with said undercut area and wherein the jet delivered by the nozzles is oriented incident against said undercut area and wherein scanning with at least one scanning member the lateral and/or front and/or rear profile of the vehicle and analysying in an analysing unit said profile obtained from said scan, said analysis unit being configured for the identification of the areas of said profile corresponding to protruding elements that form undercuts in the vehicle profile according to a lateral and/or front and/or rear projection of said vehicle, and which analysis unit controls, directly or indirectly, the positioning of the portal and/or of the support group of said at least one nozzle and/or the orientation of said at least one nozzle in a position vertically aligned with the area of said protruding element and/or with the area directly underlying the same and wherein the jet (s) of said at least one nozzle are oriented against the area that delimits said undercut, between the side of said protruding element and the wall band of the vehicle to which the said protruding element overlaps, wherein the hod provides for determining by the analysing unit the position of the undercut area thanks to a method which provides for the identification of a vertex of directional change of the line which defines the scanned profile of the vehicle and/or a jump in position of said line, in combination with a signal entered by a user relating to the indication of the presence of a protruding element of the profile and a relative undercut, said undercut area being defined on the basis of an average distance value with respect to said vertex or to said jump in position of said line of the scanned profile.