Town Car remains the only American-brand premium large sedan with rear-wheel drive. For 2006 it offers Signature, Signature Limited, and new Designer Series models, plus a limousinelike Signature L with a 6-inch-longer wheelbase for more rear leg room. All use a 4.6-liter V8 and 4-speed automatic transmission. ABS, traction control, and front side airbags are standard, but no antiskid system is available. Neither are rear airbags nor curtain side airbags. Standard features include power-adjustable pedals, dual-zone climate control, front bench seat, and leather upholstery. Among the few options are xenon headlamps and a navigation system. The Designer model is basically a retrimmed Limited.