Toyota last month started building Lexus cars in the U.S. for the first time. The cars are made in a separate section of Toyota’s sprawling Kentucky factory, a largely noiseless area where workers can hear even a click that might indicate a problem on the assembly line.

In Georgetown, getting the new Lexus production line ready meant an expansion of machinery to create an almost separate operation, even down to a separate paint shop. (Some early-stage steps like stamping panels are shared with the main factory.)

It also meant training workers in the Lexus quality-control methods, which require tighter tolerances for fitting parts compared with regular Toyotas and more meticulous painting.

The new model led to 750 new jobs, and workers spent a total of 1.5 million hours training, said Wil James, president of Toyota Motor Manufacturing, Kentucky.

Some even traveled to Japan, to train with Lexus workers at plants in Kyushu and Tahara. Others were sent to local Lexus dealerships, to observe the differences in how customers approached buying the cars they would build.

Then there is the noise at the plant — or lack of it.

The quest over the last 30 months has been to create what was unimaginable not too long ago: a largely noiseless, hushed atmosphere to house the new assembly line.

“We want our team members to be able to hear a click,” James said.