General Motors will stretch the GMC Envoy by 16 inches to fit a third row of seats in the Envoy XL, which will go into production in Moraine, Ohio, in February. The sibling Chevrolet TrailBlazer XL debuts at the same time. The roof will be raised by 3 inches to give a raised, theater-seating feel for third-seat passengers. "One of the key consumer insights in developing this vehicle was that people do not want to feel claustrophobic," said Envoy brand manager Tony DiSalle. Vehicles should be in showrooms in March or April.