Question: When did Nissan, the Acura Legend maker and the Scion xD manufacturer open US assembly plants?

Knowledge 1: Scion xD
The Scion xD is a five-door subcompact hatchback marketed in the U.S. and Canada by Japanese manufacturer Toyota beginning with the 2008 model year — replacing the xA. The Scion xD and the second generation xB were first shown to the public on February 8, 2007 at the Chicago Auto Show. The xD appeared in Scion showrooms in mid-2007 in the USA and in 2011 for Canada. The Scion xD was discontinued in 2014, and was succeeded by the Toyota C-HR in 2017. [SEP] Knowledge 2: Toyota
By the early 1960s, the US had begun placing stiff import tariffs on certain vehicles. The so - called ``chicken tax ''of 1964 placed a 25% tax on imported light trucks. In response to the tariff, Toyota, Nissan Motor Co. and Honda Motor Co. began building plants in the US by the early 1980s. [SEP] Knowledge 3: Acura Legend
The Acura Legend is a mid-size luxury/executive car manufactured by Honda. It was sold in the U.S., Canada, and parts of China under Honda's luxury brand, Acura, from 1985 to 1995, as both a sedan, which was classified as a full-size car, and a coupe, which was classified as a mid-size car (similar to how the Honda Accord is set up today). It was the first flagship sedan sold under the Acura nameplate, until being renamed in 1996 as the Acura 3.5RL. The 3.5RL was the North American version of the KA9 series Honda Legend.
Knowledge 1: Scion xD
The Scion xD is a five-door subcompact hatchback marketed in the U.S. and Canada by Japanese manufacturer Toyota beginning with the 2008 model year — replacing the xA. The Scion xD and the second generation xB were first shown to the public on February 8, 2007 at the Chicago Auto Show. The xD appeared in Scion showrooms in mid-2007 in the USA and in 2011 for Canada. The Scion xD was discontinued in 2014, and was succeeded by the Toyota C-HR in 2017. [SEP] Knowledge 2: 1973 oil crisis
Some buyers lamented the small size of the first Japanese compacts, and both Toyota and Nissan (then known as Datsun) introduced larger cars such as the Toyota Corona Mark II, the Toyota Cressida, the Mazda 616 and Datsun 810, which added passenger space and amenities such as air conditioning, power steering, AM-FM radios, and even power windows and central locking without increasing the price of the vehicle. A decade after the 1973 oil crisis, Honda, Toyota and Nissan, affected by the 1981 voluntary export restraints, opened US assembly plants and established their luxury divisions (Acura, Lexus and Infiniti, respectively) to distinguish themselves from their mass-market brands. [SEP] Knowledge 3: Acura Legend
The Acura Legend is a mid-size luxury/executive car manufactured by Honda. It was sold in the U.S., Canada, and parts of China under Honda's luxury brand, Acura, from 1985 to 1995, as both a sedan, which was classified as a full-size car, and a coupe, which was classified as a mid-size car (similar to how the Honda Accord is set up today). It was the first flagship sedan sold under the Acura nameplate, until being renamed in 1996 as the Acura 3.5RL. The 3.5RL was the North American version of the KA9 series Honda Legend.
Knowledge 1: Acura Legend
The Acura Legend is a mid-size luxury/executive car manufactured by Honda. It was sold in the U.S., Canada, and parts of China under Honda's luxury brand, Acura, from 1985 to 1995, as both a sedan, which was classified as a full-size car, and a coupe, which was classified as a mid-size car (similar to how the Honda Accord is set up today). It was the first flagship sedan sold under the Acura nameplate, until being renamed in 1996 as the Acura 3.5RL. The 3.5RL was the North American version of the KA9 series Honda Legend. [SEP] Knowledge 2: 1973 oil crisis
Some buyers lamented the small size of the first Japanese compacts, and both Toyota and Nissan (then known as Datsun) introduced larger cars such as the Toyota Corona Mark II, the Toyota Cressida, the Mazda 616 and Datsun 810, which added passenger space and amenities such as air conditioning, power steering, AM-FM radios, and even power windows and central locking without increasing the price of the vehicle. A decade after the 1973 oil crisis, Honda, Toyota and Nissan, affected by the 1981 voluntary export restraints, opened US assembly plants and established their luxury divisions (Acura, Lexus and Infiniti, respectively) to distinguish themselves from their mass-market brands. [SEP] Knowledge 3: Scion xD
The Scion xD is a five-door subcompact hatchback marketed in the U.S. and Canada by Japanese manufacturer Toyota beginning with the 2008 model year — replacing the xA. The Scion xD and the second generation xB were first shown to the public on February 8, 2007 at the Chicago Auto Show. The xD appeared in Scion showrooms in mid-2007 in the USA and in 2011 for Canada. The Scion xD was discontinued in 2014, and was succeeded by the Toyota C-HR in 2017.

Answer: 1981