The parking lot happened in two stages. In 1959 a slice of the block adjacent to the studios was demolished for the first installment.
Here's that lot outlined (# 1) in 1956 before demolition. The white building left of center in
e_r's picture is shown as # 2.
mil.library.ucsb.edu - Flight C_22555, Frame 16-22 July 1, 1956
This is the block in 1965 after the first demolition with building # 2 indicated.
mil.library.ucsb.edu - Flight C_25019, Frame 450 - November 27, 1965
This picture of that building is from sometime in the 1960's. It houses a new version of the Retake Room which came down in the first demolition.
Google Books - Culver City By Julie Lugo Cerra
By 1971 it's all gone for parking.
mil.library.ucsb.edu - Flight TG_2755, Frame 16-12 - March 1, 1971