The present invention relates to a method for producing a multicoat paint system on a metallic substrate, in which a basecoat or a plurality of directly successive basecoats are produced directly on a metallic substrate coated with a cured electrocoat, a clearcoat is produced directly on the one basecoat or the uppermost of the plurality of basecoats, and then the one or more basecoats and the clearcoat are jointly cured, and wherein at least one basecoat material used for production of the basecoats comprises at least one linear hydroxy-functional reaction product (R) having an acid number of less than 20 mg KOH/g, the preparation of which involves using at least one compound (v) containing two functional groups (v.1) and an aliphatic or araliphatic hydrocarbyl radical (v.2) which is arranged between the functional groups and has 12 to 70 carbons atoms.