[1] In an era when American automotive brands were typically restricted to building a specific car per model year, Sloan surmised that the best way to bridge the gaps was to develop "companion" marques that could be sold through the current sales network.

Cadillac, which had seen its base prices soar in the heady 1920s, was assigned the LaSalle as a companion marque to fill the gap that existed between it and Buick.

Influenced by the rakish Hispano-Suiza roadsters of the time, Earl's LaSalle emerged as a shorter, yet elegant, counterpoint to Cadillac's larger cars, unlike anything else built by an American automotive manufacturer.

[1] Built by Cadillac to its high standards but at a dedicated factory at Wyoming Road Assembly, the LaSalle soon emerged as a trend-setting automobile.

Earl's design even included a nod to the inspirational Hispano-Suiza H6, with the marque's circled trademark "LaS" cast into the horizontal tie bar between the front lights.

The LaSalles of this era were equipped with Cadillac's "Ninety Degree V-8", making the car fast, while its smaller size made it sportier and more agile.

[1] On June 20, 1927, a LaSalle driven by Willard Rader, along with Gus Bell, on the track at the Milford Proving Grounds, achieved 952 miles (1,532 km), averaging 95.2 mph (153.2 km/h), with only seven minutes given over to refueling and tire changes.

[1] In an attempt to further add exclusivity, Fleetwood convertible coachwork selections were further distinguished by the descriptions "Fleetcliffe", "Fleetlands", "Fleetway" and "Fleetwind" which didn't continue for 1931.

Fisher and Fleetwood coachwork choices were again changed based on popularity, and additional optional equipment was added retaining the 134" wheelbase used the previous year.

Again, Earl's work with the LaSalle resulted in a graceful vehicle, led by an elegantly thin grille that now concealed the previously exposed radiator, which was shared with Cadillac and Pontiac for that year.

[1] 1933 was the first year all GM vehicles were installed with optional vent windows which were initially called “No Draft Individually Controlled Ventilation” later renamed "Ventiplanes" which the patent application was filed on Nov. 28, 1932.

[1] The final 1940 LaSalles were introduced in October 1939 with a full array of semi-custom body styles, as it had in its first year, including a convertible sedan.

One was based on the notchback GM C platform, which ended up being shared by the Cadillac Series 62, the Buick Roadmaster and Super, the Oldsmobile 90, and the Pontiac Custom Torpedo.

A second was based on the fastback GM B platform, which was eventually shared by the Cadillac Series 61, the Buick Century and Special, the Oldsmobile 70, and the Pontiac Streamliner Torpedo.

[1] The Great Depression, combined with LaSalle's stalling sales numbers, caused Cadillac to rethink its companion make.

[1] While the introduction of LaSalle showed there was a market for a luxury car that was more conservative in appearance and price, GM already had Buick which filled that role very successfully.

[4] The introduction of the "Art and Colour Section" headed up by Harley Earl and a shared design theme in all GM products further complicated the brand distinction between the original brands in that the only differences among Oldsmobile, Buick, LaSalle, and Cadillac were exterior design appearance, wheelbase length, and colors, while charging extra due to marketing and pricing objectives.

GM instead emphasized styling over engineering advancement for the decades that followed and did not bring "an aluminum block, fuel-injected, overhead-cam V-6 into production until 2004".

[6] Cumberford described the Roadster as "a signpost to the many wrong turns that led to the bankruptcy of what was in 1955 the largest business entity in the entire world (GM)".

[citation needed] Early mockups of what was to become the 1963 Buick Riviera were badged "LaSalle II," as the Cadillac division was being considered for production of this successful personal luxury car.

In the 1970s television show All in the Family, Archie and Edith Bunker sing, "Gee, our old LaSalle ran great" in the program's opening theme song, "Those Were the Days."

This is the car that the character Marcus Brody drives when he visits Indiana Jones in the film Raiders of the Lost Ark (1981).

Griffin’s WW2 novel Semper Fi [11] includes a detailed subplot about a young marine’s cunning scheme to purchase a nearly-new LeSalle from an unscrupulous car dealer.

Those Were The Days theme song of tv show All in The Family Lyrics include “gee our old LaSalle ran great.”