A process for improving the intercoat adhesion in a multicoat paint system utilizing a primer coat, an aqueous basecoat, and a clearcoat, where the multicoat paint system has been produced by means of a wet-on-wet technique. The clearcoat is produced using a pseudoplastic powder clearcoat slurry prepared by a secondary dispersion process or a melt emulsification process. The aqueous basecoat material used to produce the aqueous basecoat comprises a dispersed graft copolymer whose particles are composed of a hydrophobic core of copolymerized olefinically unsaturated monomers and of a hydrophilic shell which comprises a polyurethane, where said copolymer is prepared by free-radical (co)polymerization of the monomers in the presence of at least one polyurethane containing specially selected olefinically unsaturated groups.