The Buick Estate was a line of full-sized station wagons manufactured by the Buick division of General Motors. As its premier luxury division, Cadillac, didn't offer a station wagon, the Estate was GM's most expensive and most fully equipped entry in the market.
Early history
The first Buick Estate station wagon was a large-bodied GM C platform Super modified with a wooden body, shared with the Oldsmobile Series 60. In 1941 and 1942 it was available on Buick's B platform Special series, and later on Buick's C platform (Roadmaster and Super) in the 1946–53 model years. From 1954 to 1958 it was only offered on the smaller B platform Century and Special, with all steel bodies. Among these were hardtop Estate Wagons called Caballero that were offered only in 1957 and 1958.
From 1959 through 1964 the Estate Wagon was offered on the B platform Invicta and LeSabre. In 1965, the Estate Wagon was replaced by the new, smaller A platform Buick Sport Wagon, making the B-body Chevrolet Impala Estate and Pontiac Safari the only full-sized GM station wagons until 1970.
First generation (1970)
The Buick Estate wagon was re-introduced as the top-level luxury station wagon for GM in 1970 to compete against the Mercury Colony Park and Chrysler Town & Country. Buick's first full-sized station wagon since 1964, it was available as a separate series on the B-body LeSabre and Wildcat, sharing their 124.0-inch (3,150 mm) wheelbase, basic body and interior. The LeSabre Custom's bright rocker, wheelhouse and rear lower fender moldings were used. Woodgrain was an option for the body sides, incorporating the traditional "Sweepspear" feature. Interiors were all vinyl in a Custom grade. Despite being on the B-body it shared the C-body division flagship Electra's 455 cubic inch V8 and four VentiPorts on the front fenders. The following year the Estate would move up to Electra's larger body and more voluminous interior.
Source: Wikipedia