Continuity mistake: All three surfers at the start are bare footed, but once on the beach and after, they have footwear - in a supposedly continuous scene.
Revealing mistake: When Bond climbs onto the bigger hovercraft, the smaller one overturns and you can see it's an obvious dummy sitting in the back.
Factual error: The invisible car cannot possibly work as it is described in the film, by projecting an image of things that are 'behind' the car onto the side that is being viewed. This ignores parallax effects - the things that are 'behind' the car change, depending on the distance and angle from which the car is being viewed. Two people standing next to each other, on the same side of the car, would need to see two entirely different images projected.
Continuity mistake: When Jinx takes a sip of her drink, Bond says to her, "Too strong for you?" and you can see takes the glass away from her mouth, but in the next shot she is holding the glass close to her lips.