With speculation mounting that Volkswagen’s mid-engined Bluesport roadster concept from last month’s Detroit Auto Show might be headed for production, there are a growing number of reports that suggest sister brands Audi, Seat, and possibly even Porsche, may also get their own version of the car.

The strongest indication that several variants of the roadster may be produced came from VW executive Ulrich Hackenburg, who told reporters at the Detroit event that the business case for the car could also be successful if its investment was shared with at least three brands.

This ties in with previous reports that claimed Audi is planning a lightweight roadster as well as a range of new ecological yet sporty models, and a car based on the Bluesport roadster concept but wearing an Audi badge looks entirely plausible.

This latest computer generated rendering gives us a preview of what such a car could look like, picking up cues from the bigger R8 but maintain the chiseled appearance of the Bluesport.

If given the green light, the car likely wouldn’t appear until after 2011. To speed up development, powertrain options would likely include current VW Group TSI and TDI four-cylinder engines mated with manual or DSG dual-clutch transmissions.