I was just going to mention the same thing about the performance trim not having folding seats. Not sure why they did this either...The luxury and premium trim levels have folding rear seats. Standard and performance do not. Doesn't make a lot of sense (clearly it isn't based solely on price). Some e36 M3/4s had non-folding rear seats. Those cars are now in High demand because of the increased structural rigidity. Don't know what BMW's intent was. I highly doubt Cadillac was thinking structural rigidity when making the folding/non-folding seat decision.
BUMP.It's absolutely ridiculous that folding rear seats are not standard, as they are on even the cheapest car. I learned the hard way... wife bought curtain rods and when I went to fold down the rear seats, I discovered they wouldn't fold and didn't even have a passthrough.