For me I can't think of a small project but the toughest thing was getting all the sheetmetal installed with the correct gaps prior to painting and mostly afterwards. From the door to fenders, valances, hoods, headlamp doors, etc. I would have it done one day then look at it the next day and say I can get it a little better. I must have tweaked everything everyday for a week. I even put a dent in a completed fender pushing it in. Thank goodness for a great PDR guy that I had. Would never know it was there.
Dave