As the basis for premium sedans, General Motors could spend the money to make it properly light and strong through the use of high-strength steels. The Chevy sport sedan mentioned would be "a kind of four-door Camaro" – Pontiac G8 GXP redux, anyone? – while the Buick only gets described as "cushier," and both would go on the shorter wheelbase Zeta.
The most interesting tidbit could be Cadillac's use of the long-wheelbase platform. MT prices a Cadillac flagship at between $125,000 and $140,000 and says the Zeta-based Cadillac, Whitacre's S-Class rival for the Crest-and-Wreath brand, will sit beneath it. If it all comes to pass, that would give Cadillac a larger CTS, then an XTS, then a properly sporting high-end luxury competitor, then a one-Caddy-to-rule-them-all ne plus ultra model by 2014 or so. Hat tip to Joshua!
[Source: Motor Trend]