When the bad guy opens the door on Kelly taking pictures on his documents, she turns around abruptly, and her hair is completely messed up. In her next frame, she has been perfectly coiffed again, bangs neatly parted on either side of her forehead, and her locks have been glossed over so not a strand sticks out of place.
Bosley complains that his wife packed brown shoes with a tuxedo. In Circus of Terror (1977), when asked if he's married, he replies, "Not lately." In Angels Ahoy (1978) he says he's never been married.
After Sabrina is nearly driven off the road she returns to Mr. Anderson's beach house and parks in full daylight. A moment later when she enters the house it is clearly dark outside. When the Angels emerge from the house together it is light again.
Regarding the car-chase scene... the damage to Sabrina's driver's side "comes and goes."
The bad guy drives his car off the cliff and Sabrina stops her car. But the film has accidentally been flipped and it appears she is driving from the passenger seat.
Jill removes a bandage off her hand and puts it against the door mechanism, so that it will stay unlocked, even when the door is shut. Then, she waits outside for the maid to come out. But when the housekeeper closes the door, she pulls on it and it is shut tight. Then Jill simply pulls on it and it opens. The door should have opened easily for the housekeeper, when checked it. Then Jill exits, doesn't remove her bandage from the door, and yet the housekeeper has to unlock it to reenter. The bandage trick magically only works for Jill.
Once again, a car going off a cliff explodes from the passenger compartment, without the car hitting anything before the explosion.
When the guy chasing Sabrina goes off the cliff (a man-made structure, of sorts), some "ramps" are visible as he goes over.
BTW, his car explodes almost in mid-air... the front end had hardly touched the ground.
(Oh, a different car, of course.)