Cadillac will have an upmarket coupe to take on the BMW 6-series around 2009/2010, and it'll be based on this, the CTS Coupe concept. This muscular coupe was one of the true surprises of the Detroit show, GM managing to keep the car a secret until Sunday evening, when news of it leaked out online.“This is the first time anyone outside GM has really seen the coupe, so its going to be interesting what he reaction will be,” said Jim Taylor, Cadillac’s boss.From where we’re sitting the design manages to combine muscularity with elegance. The beef comes from the powerful haunches and raised bonnet, the latter shared with the CTS-V also revealed at Detroit. The elegance comes from the sweeping roofline and curvaceous whelarches. One rival designer reckoned the steeply-sloped rear screen was one of the most aggressive he’d ever seen, veering toward a supercar rather than a coupe.Cadillac is expected to make its mind-up about production over the next few months, according to Taylor. Although he confided that the car was pencilled in to his wish list for future Caddy models. “Now its a matter of getting engineering and design together to see whether we can do this model.” A production coupe could be engineered as quickly as 12 months, putting a production date in the middle of 2009.Right-hand drive is guaranteed. “Bob Lutz has said we’ll engineer all future cars for both lhd and rhd and the new CTS platform is just like that,” said Taylor.Its unikely though that a CTS-V version of the coupe would be rhd. GM is sticking to the line that the CTS-V saloon will be lhd only, and it's safe to assume that any V-badged coupe would be the same.