You're looking at the inspiration for the rear drive architecture that will enable Cadillac to build a legitimate BMW 3 Series rival - and might underpin sporty compact rear drive cars for other GM divisions. The car shown here is the Holden Torana TT36, a concept developed by GM's Australian division and unveiled at the 2004 Sydney Motor Show.
Smaller than the Zeta-based Holden Commodore, the TT36 was built using hardware from the Pontiac Solstice's Kappa architecture. Holden boss Denny Mooney has made it quite clear a production version could be developed using Kappa components: "We were looking at that hardware as a potential base," he told the Sydney Morning Herald last year, "...to do a sedan off that. That's fundamentally what we'd do."
Scale clay models of the Torana TT36 concept, which was developed under the codename XP54, were shown to GM product czar Bob Lutz, design chief Ed Welburn and then North American engineering vice-president Jim Queen (now vp of global engineering) in February 2004. Mooney wanted GM to okay development of the TT36's "unique lower dominant structure" (i.e. platform), but the program was reportedly put on ice while the company diverted resources to rushing the GMT900 trucks and SUVs into production. Now it appears to have been given the green light.
The TT36 concept was fitted with a twin-turbo version of GM's 3.6-liter "high-feature" V-6 developing a claimed 375-hp and 354 lb-ft, driving the rear wheels through a six speed manual transmission. But Mooney said production versions could also be four-cylinder powered. GM's Ecotec inline four has already been adapted for rear drive use in the Solstice and Saturn Sky, with the 2.4-liter naturally aspirated version developing 177-hp and the 2.0-liter turbo a useful 260-hp. And we hear GM has 300-hp Ecotec turbos under test.
The BMW 3 Series uses MacPherson struts up front, so no rocket science there. GM would likely follow suit to keep costs under control, and match BMW's multi-link rear end with a suspension derived from the Kappa's upper and lower control arm set up. GM might need to up the front disc brakes from the 11.7-inch rotors used on the Kappa roadsters by an inch or so to handle the extra mass of a sedan, but otherwise Kappa components such as hubs and axles and steering gear could be used or readily adapted.
Mooney has publicly claimed production versions of the TT36, powered by either four or six cylinder engines, could be brought to market for the equivalent of $20,000 to $30,000. That's right in the window of where GM needs to be to slide a smaller rear drive Caddy in under the next-gen CTS's entry level price point here in the U.S., and to make it a viable 3 Series rival in Europe. It also opens up the small possibility of lower volume, four and six cylinder Pontiac variants positioned between the front drive G6 and the Commodore sized G8 (G7, anyone?).
Intriguingly, Mooney has just been promoted from running Holden. His new job? Effective August 1, Mooney will move to the newly created position of global vehicle systems and integration, reporting to ... Jim Queen. Mooney will work with GM regional engineering leaders to ensure the execution of best practices across GM's global engineering organization.