When they park the cruiser at the beach, the gold Mustang is parked there already.
The woman towing the pumpkin is Erin Fleming, who was later infamous as Groucho Marx's abusive live-in manager.
Erin Fleming's character, the pumpkin woman, is listed as Suzanne Martin in the end credits, but her name is not mentioned.
311W = indecent exposure, woman.
390 down = drunk and unconscious.