Question: When did the company that built VTEC, the owner of Scion, and Nissan open US Assembly plants?

Knowledge 1: Scion (automobile)
Scion is a discontinued marque of Toyota that started in 2003. It was designed as an extension of its efforts to appeal towards younger customers. The Scion brand primarily featured sports compact vehicles (primarily badge engineered from Toyota's international models), a simplified "pure price" model, and eschewed trim levels in favor of offering a single trim for each vehicle with a range of factory and aftermarket options for buyers to choose from to personalize their vehicle. The "Scion" name, meaning the descendant of a family or heir, refers both to the brand's cars and their owners. The brand first soft launched in the United States at selected Toyota dealers in the state of California in June 2003, before expanding nationwide by February 2004. In 2010, Scion expanded into Canada. In an effort to target the generation Y demographic, Scion primarily relied on guerrilla and viral marketing techniques. [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: VTEC
VTEC (Variable Valve Timing & Lift Electronic Control) is a system developed by Honda to improve the volumetric efficiency of a four-stroke internal combustion engine, resulting in higher performance at high RPM, and lower fuel consumption at low RPM. The VTEC system uses two (or occasionally three) camshaft profiles and hydraulically selects between profiles. It was invented by Honda engineer Ikuo Kajitani. It is distinctly different from standard VVT (variable valve timing) systems which change only the valve timings and do not change the camshaft profile or valve lift in any way.
Knowledge 1: Scion (automobile)
Scion is a discontinued marque of Toyota that started in 2003. It was designed as an extension of its efforts to appeal towards younger customers. The Scion brand primarily featured sports compact vehicles (primarily badge engineered from Toyota's international models), a simplified "pure price" model, and eschewed trim levels in favor of offering a single trim for each vehicle with a range of factory and aftermarket options for buyers to choose from to personalize their vehicle. The "Scion" name, meaning the descendant of a family or heir, refers both to the brand's cars and their owners. The brand first soft launched in the United States at selected Toyota dealers in the state of California in June 2003, before expanding nationwide by February 2004. In 2010, Scion expanded into Canada. In an effort to target the generation Y demographic, Scion primarily relied on guerrilla and viral marketing techniques. [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: VTEC
VTEC (Variable Valve Timing & Lift Electronic Control) is a system developed by Honda to improve the volumetric efficiency of a four-stroke internal combustion engine, resulting in higher performance at high RPM, and lower fuel consumption at low RPM. The VTEC system uses two (or occasionally three) camshaft profiles and hydraulically selects between profiles. It was invented by Honda engineer Ikuo Kajitani. It is distinctly different from standard VVT (variable valve timing) systems which change only the valve timings and do not change the camshaft profile or valve lift in any way.
Knowledge 1: Scion Fuse
The Scion Fuse is a concept car created under one of Toyota's brands, Scion. The Fuse was built by Five Axis Models in Huntington Beach, CA with assistance from MillenWorks. It was first introduced at the 2006 New York International Auto Show. According to Scion, the Fuse is a 2-door coupe with 4 seats and swan doors for clearer ground clearance. [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: VTEC
VTEC (Variable Valve Timing & Lift Electronic Control) is a system developed by Honda to improve the volumetric efficiency of a four-stroke internal combustion engine, resulting in higher performance at high RPM, and lower fuel consumption at low RPM. The VTEC system uses two (or occasionally three) camshaft profiles and hydraulically selects between profiles. It was invented by Honda engineer Ikuo Kajitani. It is distinctly different from standard VVT (variable valve timing) systems which change only the valve timings and do not change the camshaft profile or valve lift in any way.

Answer: 1981