(CNN) What started out as a simple game between a father and son turned into a Christmas surprise of a lifetime from Italian supercar maker Lamborghini for a family from Erie, Colorado.

Sterling Backus, 54, and his 12-year-old son Xander were playing the racing simulation video game "Forza Horizon 3" one day when Xander asked his father if they could build their favorite car: a Lamborghini Aventador.

Backus, who is a physicist at Thorlabs, told CNN that he "has always been a Lamborghini guy" and that he did not hesitate when his son asked.

Sterling Backus and his son Xander used a desktop 3D printer for most of the parts.

The two started planning out their ambitious project in February 2018, and it resulted in a surprise call two months ago from Katia Bassi, who is the chief marketing officer of Automobili Lamborghini.

"I was shaking in my boots since it was like getting a call from the Pope and he is coming to dinner," Backus told CNN. "Of course, a metaphor, but just to give (you) the idea of the gravity to me, personally."

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