Aqueous coating composition comprises (wt.%) an aqueous binder mixture (A1) comprising a secondary, hydroxy-functional polyacrylate dispersion or polyacrylate emulsion (a1) (25-70), aliphatic polyurethane dispersion (a2) (5-50), hydroxy-functional polyester-polyurethane dispersion composed to an extent of at least 75 wt.% of a polyester of molecular weight 500-2500 g/mol (20-70); and at least one cross-linker (A2), necessarily including at least two of the three components (a1)-(a3), and necessarily including one component (a1) and/or (a3) in an amount of at least 35 wt.%. Independent claims are included for the following: (1) anti-chip base coats comprising the aqueous coating composition; and (2) paint system comprising a substrate and at least one coat composed of the aqueous coating composition.