I would really love for the XLR to return as a proper Cadillac ! The next XLR should be based on a Cadillac specific RWD platform not based on the Corvette . For the amount they would charge for the car it should be a Cadillac and nothing else .I hope that if they build a new one that they fix the one major flaw and give the car an interior that is at the proper level of quality and materials that it's competitors are at . I loved the XLR but the interior was really it's weak link .
If you ever see one again it will be based on Alpha (the ATS) not on the C7. Y-Body will stay a Corvette exclusive after the last disaster with the XLR.
Besides I think an Alpha Roadster would be a better fit for Cadillac since you don't have to rely on the specific proportions of the Y-Body (high center tunnel, low slung roof, rear mounted transmission, limited cargo options in the back).