Cadillac is to ditch its unsuccessful Saab-based BLS and build a striking new rear-drive saloon in its latest bid to rival BMW’s 3-series and Audi’s A4.Called Project Alpha and due in Europe in 2011, the new car will be a key part of General Motors’ latest efforts to make Cadillac a global player. But it will use a rear-wheel drive platform that is currently under development in the US. That platform, also called Alpha, is a development of the chassis that formed the basis of the Holden Torana concept.Although Holden is now at the centre of GM’s rear drive operations (its Holden Special Vehicles offshoot already builds the G8 for Pontiac), sources say Project Alpha is being engineered in the US, as Holden deals with large rear-drive cars.A proposed technology-sharing deal with Alfa Romeo, which would have given the Italian brand access to Cadillac’s rear drive platforms, was described as having “fallen by the wayside” by our source. The styling will be a variation on the razor-edge look previewed by the CTS coupé concept at this year’s Detroit show. A GM source who has seen the car described it as “a shrunken version of the coupé” with a more aggressive front end than the CTS saloon’s. Engine choices are likely to include a V6 petrol for higher-end models and a four-cylinder diesel. There could also be a four-wheel-drive V-spec model that would provide a rival for the M3 and Mercedes’ C63 AMG. Along with a four-door saloon, Cadillac is working on coupé and cabriolet versions, although these models have not been signed off for production yet. The new car will not be a direct replacement for the BLS, the rebodied Saab 9-3 designed specifically for the European market. Instead, Alpha will move upmarket in a bid to grab some of the sales volume enjoyed by the likes of the 3-series. To that end, a lot of effort is being put into developing the handling to appeal to European drivers. Alpha is said to have its own suspension, rather than a reworked version of the MacPherson strut and four-link rear set-up seen on the Zeta large-car platform that will also be used on the next Camaro.Project Alpha is part of GM’s plan to improve Cadillac’s image outside of the US. In Europe, the perception of Cadillacs as oversized V8 American barges is still putting off buyers.