The new sports car was called the XLR (Wikipedia entry here). It was marketed over the 2004-2009 models years with modest success. GM's bankruptcy might have been a factor in its demise, but slow sales and the fact that it was based on an old (1997-2004 Corvette C5) platform were equally likely factors.
Given the constraints of the C5 layout and the angular, faceted Art & Science styling theme, Cadillac stylists did about as well as might be expected. That is, the XLR in my opinion was not a styling success. Seen on streets and highways, XLRs have the appearance of a flattened, almost Roman style brick. I don't think sports cars should look like bricks.
A collection of C5 Corvettes to illustrate what Cadillac stylists had to work with.
Most publicity photos of XLRs are shot from an unnaturally low point of view (see images below). I include this photo because it is taken from something close to normal eye-level. Compare to the Corvettes in the previous image.
The grille / front ensemble is nicely done, combining Cadillac themes and the low body. But see how flat the hood is.
A somewhat flattering photo due to the camera position. It makes the car seem taller and less flattened than it actually is.
In profile, the XLR shows off its slightly wedged appearance. Room is needed at the rear for luggage and the retractable top. The hood line is so low that the front wheel openings create a pinched fender area above them despite being slightly offset by the thick lips of the openings.
The trunk top, like the hood, is nearly flat. With the top raised and given the shallow Vs of the bumper, license plate ensemble, and especially the central brake light, the trunk comes very close to having a dished-in appearance. I would have been tempted to either slightly raise or lower the rear fenders and tail lights to offset the effect of the broad, nearly-flat plane. Other small deviations from a brick-shape also might have helped the design.