How much of the CTS Coupe will change for production? is reporting that they asked that question of GM Insiders and got a surprising answer. CTS Coupe'Very little' is the basic answer. All the sheet metal you see on the concept will be there on the production car. Changes will be limited to a more typical dual exhaust, production wheels, and slight reshaping of the rear bumper for better low speed impact protection at the corners. This appears to be the ultimate expression of the changes within GM that Bob Lutz brought about when he forced the company to revisit their most entrenched rules of design. The example given is that the design 'rule book' would not have allowed them to lower the roof (MT says 2" though I had heard that the roof was 4" lower than the sedan) this much because it would have violated the company's arbitrary visibility rules. If this is what you can get when you put styling and design above cost and decades-old rules - bring it on! Read the MT article at: Cadillac CTS Coupe Concept: Breaking the Rules