Bullitt - Murder At The Thunderbolt Hotel
The police learn that on the day he arrived in San Francisco the murdered state's witness Ross had called a woman, Dorothy Simmons, at the Thunderbolt Hotel in San Mateo. Bullitt bums a ride from Cathy and they head down there.
Then ... Cathy's yellow Porsche drops him off at the hotel entrance and she waits in her car while he goes inside.
... more recently, the hotel was known as the Thunderbird hotel in the early 1960s but renamed the Thunderbolt by the time the movie was filmed (see reader Tom's comment). It then became for many years the Clarion Hotel, 401 E. Millbrae Avenue, Millbrae, alongside Highway 101 just south of San Francisco airport (map). The distinctive billboard was retained (below), clearly visible from the freeway.
... and Now, in 2012 the Clarion became part of the Aloft chain and received a major makeover.
... a vintage postcard ... in this 1964 postcard aerial image of the hotel there is a different billboard (at bottom right) and the name 'Thunderbird' is on the left of the entrance.
Then ... At the concierge desk Bullitt flashes his badge and asks to be taken to the woman's room. The panning camera gives us a sweeping view of the hotel lobby.
When more police arrive a nervous Cathy rushes after them - the pool is behind her so she was running across the lawn (see aerial image above) towards the rear wing ...
... she enters the room and is horrified to see the woman prostrate on the floor, strangled just moments earlier.