TOKYO — Lexus is ready to spring the next development in the compact IS story, according to sources in Japan.

North America has already welcomed the impressive new 2006 IS 250 and IS 350 sport sedans. But at January's Detroit show, Lexus will unveil a concept teaser pointing to a sleek and different new IS coupe/cabrio, sources say.

A successor to the U.S.-designed LF-C concept displayed at the 2004 New York Auto Show, the Detroit 2006 IS concept is much closer to production, it's said, and points to what will be appearing in U.S. showrooms in August 2007.

Complete with power-operated top, the Detroit car reportedly packs a 5.0-liter V8 with 450-hp output. This will be a bored-out version of the 4.6-liter V8 from the new Lexus LS 460 premier sedan, which will have its official production launch at Detroit. Lexus is also tipped to be readying an IS 500 sedan to target the likes of the Mercedes C55 AMG and BMW M3.