reworking a fully restored car

Well I thought I had this thing licked but I showed it to a friend yesterday and it turns out there is three oval patches about 4 inches long that have cracked like a dry river bed DOH ! the paint supplier showed me the manufactures sheets and apparently I did something wrong either to thick on the base coat or not enough flash time for the temp between coats or a full moon who knows but it looks like I will be sanding and recoating from scratch ie.. primer , paint , clear -eff me gently .