A fast hardening clear coating composition for repairing a clear coat/color coat finish or a pigmented mono-coat of a vehicle comprising a film forming binder and an organic liquid carrier, where the binder contains a hydroxyl polymer component comprising (A) hydroxyl-containing acrylic polymer, (B) at least one hydroxyl-terminated component selected from the group consisting of (1) an organic diol having the formula where R1 and R2 are individually selected from the group of hydrogen and an alkyl group having 1, 3-5 carbon atoms and (2) a hydroxyl terminated reaction product of trimethylol propane and a lactone; (C) an organic polyisocyanate crosslinking component, at least portion of which comprises a trimer of isophorone diisocyanate or hexamethylene diisocyanate and the composition further contains, a curing catalyst, of a dialkyl tin aliphatic carboxylate, a tertiary aliphatic mono or diamine, an aliphatic carboxylic acid, and optionally, a zinc or calcium organic acid salt in an effective amount such that the coating composition on curing at ambient temperatures is in a water spot free and sufficiently hard state for sanding or buffing within about 2 hours after application or on cool down when baked under normal conditions.