Rolls-Royce Motor Cars is adding shifts and extending hours through the end of the year at its Goodwood, U.K., assembly plant to meet demand for both its 4-door Phantom sedan and Phantom Drophead Coupe convertible.

Rolls says orders for the 4-door "stretch well into 2008," and the backlog for the Phantom Drophead Coupe extends "right through next year."

Retail sales for the brand overall are up 22% over 2006 levels through September, the auto maker says.

Last week, Rolls announced it would launch a production version of the 2-door, 4-seat 101EX beginning next summer. That car bowed in concept form at the Geneva auto show last year.

It also is readying Goodwood for launch of a new model line that will be smaller and presumably less expensive than the Phantom. Rolls says that move will require the addition of several hundred workers at the plant.

"These are exciting times for Rolls-Royce," Chairman and CEO Ian Robertson says. "With the success of Phantom, the recent addition of the convertible and last week’s announcement of a new coupe in the Phantom family, our challenge is to cope with exceptional customer demand."

Further details on the expansion of Goodwood for the production of the new model "will be released in due course," the auto maker says.

Rolls has sold 2,693 Phantoms since the car was launched in 2003. Sales last year totaled 805, up from 796 in 2005. The Phantom is the first Rolls produced under BMW AG ownership.