Mexico accounts for a fifth of all vehicle production in North America and has attracted more than $24 billion in auto investment since 2010, according to the Michigan-based Center for Automotive Research.

Auto assembly is projected to more than double in size between 2010 and 2020 as carmakers invest around $13 billion to move 3.3 million units of capacity from Japan, Germany and South Korea. Carmakers are attracted by Mexico's unique free trade position as well as lower labor costs.

Below are some facts on the operations of the main global carmakers with plants in Mexico. Production figures are according to the Mexican Automotive Industry Association.

NISSAN (>> Nissan Motor Co Ltd)

2015 production: 822,948 vehicles

Nissan is the largest automaker operating in Mexico. It built its first overseas plant in Mexico 50 years ago and now produces mainly its entry-level Versa and Sentra sedans there. It exports roughly half of its output to the United States, where it also has production plants. Nissan and Renault Chief Executive Carlos Ghosn said this month he was watching the incoming Trump administration closely and would respond to whatever policies it adopts.

GENERAL MOTORS (>> General Motors Company)

2015 production: 690,446

Trump has criticized GM for building cars in Mexico while laying off workers in the United States. GM said in 2015 it would invest $350 million to produce its next-generation Chevrolet Cruze compact cars in Mexico, as part of a $5 billion investment in its Mexican plants announced in 2014, creating 5,600 jobs. It has defended the arrangement as part of its strategy to serve global customers. In November, GM said it planned to lay off 2,000 employees at two U.S. auto plants in early 2017. When asked earlier this month about the company's plans for investments in Mexico, GM CEO Mary Barra said she could not comment, but emphasized a willingness to cooperate with the incoming Trump administration.

FIAT-CHRYSLER (>> Fiat Chrysler Automobiles NV)

2015 production: 503,589

Fiat Chrysler CEO Sergio Marchionne said this month that uncertainty over Trump's trade and tax policies could lead automakers to delay investments in Mexico, and confirmed plans to create 2,000 jobs at his company's U.S. factories with an investment of $1 billion. He said he had not made a decision on whether to move production of certain Ram heavy-duty pickups from Mexico to the Unites States. "If tomorrow morning President-elect Trump decides to impose a border tax on anything that comes up from Mexico, then we'll have to adjust," he said.

VOLKSWAGEN (>> Volkswagen AG)

2015 production: 457,517

Volkswagen has had a plant in Mexico for 50 years and is not shifting any jobs to Mexico from the United States. It has around 16,500 employees in Mexico, who built 345,000 engines as well as cars in 2015. In the United States, it has around 3,200 workers at its plant in Chattanooga, Tennessee which built 87,000 cars in 2015. It plans to invest $7 billion in the United States between 2015 and 2019. Its Audi luxury car brand opened a $1.3 billion factory in Mexico last year, its first in the country and eventually slated to be its only source globally for its Q5 SUVs. It plans initial production of 150,000 cars a year.

FORD (>> Ford Motor Company)

2015 production: 433,752

Ford scrapped a planned $1.6 billion Mexican car factory this month and added 700 jobs at a cost of $700 million in Michigan following criticism by Trump. It said it was a response to a decline in North American demand for small cars like those that would have been made at the plant, and CEO Mark Fields said Ford would have made the same decision even had Trump not been elected. Ford still plans to shift production from Michigan of its Focus compact car to an existing plant in Mexico.

HONDA (>> Honda Motor Co Ltd)

2015 production: 203,657

Honda has two auto plants in Mexico, which together build around 100,000 motorcycles a year as well as cars. Vehicles made in Mexico comprise less than 10 percent of Honda's total U.S. vehicle sales. Honda said in October it was shifting production of the new generation of its CR-V sport utility vehicle to the United States from Mexico. But its president said it had no immediate plans to curb production in Mexico, preferring to wait until after Trump's inauguration.

MAZDA (>> Mazda Motor Corp)

2015 production: 182,357

Mazda began producing cars in Mexico in 2014, with production of the Mazda3 sedan for the United States. Vehicles made in Mexico comprise around 30 percent of Mazda's total U.S. vehicle sales.

TOYOTA (>> Toyota Motor Corp)

2015 production: 104,810

Toyota plans to raise output from its plant in Baja California, Mexico to around 160,000 units by 2018. It is also building a plant in Guanajuato city which will have an annual capacity of 200,000 when it comes online in 2019. Trump took on Toyota earlier this month, warning the world's largest automaker that it would face a "big border tax" if it exported Mexico-built cars to the U.S. market. Toyota President Akio Toyoda said in response: "We're always considering ways to increase production in the United States, regardless of the political situation." Vehicles made in Mexico comprise less than 10 percent of Toyota's total U.S. vehicle sales. But it has said its Guanajuato plant under construction in Mexico will produce the entry-level Corolla sedan, a vehicle segment currently produced at its plants in Mississippi, Missouri, and Ontario, Canada.

Toyota plans to invest $10 billion in the United States over the next five years, the same as in the previous five years.

KIA (>> Kia Motors Corporation), HYUNDAI (>> Hyundai Motor Co)

Kia is building a $1 billion plant in Mexico, with a capacity of 300,000 vehicles a year, to cater for demand from North and South America. Affiliate Hyundai also plans to build its Accent small car at the Kia factory this year, two people familiar with the matter have told Reuters, shifting output out of high-cost South Korea. It will be the first Hyundai car to be made in Mexico.

BMW (>> Bayerische Motoren Werke AG)

BMW is building a new plant in Mexico, where it plans to invest $2.2 billion by 2019 for annual production of 150,000 cars, with the output intended for the world market. It also has sizeable factories in the United States, where it builds higher-margin SUVs for export to Asia and Europe.

DAIMLER (>> Daimler AG)

Daimler has said it plans to begin assembling Mercedes-Benz vehicles in 2018 from a $1 billion facility shared with Renault-Nissan (>> Renault), (>> Nissan Motor Co Ltd) in Aguascalientes in Mexico.

(Reporting by Georgina Prodhan, Edward Taylor and Andreas Cremer; Editing by Keith Weir)