Plot hole: Goldfinger wasn't planning on Mr. Solo breaking away from the rest of the gangsters before Goldfinger could have them all killed by the nerve gas so it makes no sense that there would already be a truck from the stud farm waiting for Oddjob to drive back with the remains of the crushed car. It also begs the question if Oddjob had to drive the truck back to the farm where is the guy that drove it to the junkyard in the first place?
Plot hole: When Bond goes into the kitchen for the champagne, Oddjob is waiting for him. But where was he hiding? Oddjob couldn't have hidden in the bedroom without being seen. The kitchen is separated from the bedroom about halfway by a metal grate and not a wall. Oddjob could have only been hiding in front of the cupboards since we can see Bond from the bedroom POV all the way to the refrigerator. There is no possible way Bond wouldn't have seen him or even brushed against him. There is lighting in the kitchen, which we know because Bond is illuminated when he walks in; he casts a strong shadow on the floor during and after his fall (not from the refrigerator); and is illuminated when he stumbles out. The pan shots of the kitchen show no places where Oddjob could have concealed himself - and he is not exactly on the thin side.
Plot hole: As Goldfinger points out there are 41,000 troops stationed at Fort Knox so how in the world was Goldfinger able to make his escape? The troops should have easily been able to overpower Goldfinger's men without much of a fight and certainly shouldn't have been so easy for Goldfinger himself to get away on the helicopter.
Plot hole: The planes spraying the gas are flying too high and too fast for the gas to be able to have any effect on the soldiers on the ground as quickly as it does. While we later find out that the soldiers were faking the effects, the too-rapid response should have raised the bad guys' suspicions.
Plot hole: Jill was sprayed with liquid or atomized gold. Yet there is no overspray anywhere, no paint on the bed or sheets, no dripping from Jill's arm to the carpet. Even if the paint was quick-dry, there would have been some paint residue just from Oddjob moving her around to spray her whole body.