Petulia - Motel Check-in
Archie goes along with Petulia's suggestion that they go to a hotel - they take a cab to a motel with a novel TV check-in kiosk which automatically dispenses their room key. (Note the psychedelic poster on the cab advertising a concert for Eric Burdon and the Animals, a popular British group at that time).
Then ... This scene was filmed at the garage entrance of the San Francisco Hilton Union Square Hotel at 200 Ellis Street, near Mason. The motel was designed to let guests drive inside the building up to their floor and park close to their room, as they still do today.
... in 1964, in this vintage photo below, the same entrance
.... and Now, the check-in window today is a mural sporting a large Hilton Logo.
... and Now, the garage entrance (on the left) on Ellis Street.