When Onslow arrives at the church, he pulls up to the gate, the exact spot where Richard had parked and locked his car. In the next shot, you see that Richard's car has magically moved up the street.
Hyacinth is always seen cleaning things in her house, and she insists that everything be spotless. At the opening of this episode, she is at her bedroom mirror, and there are spots and smudges on the mirror.