I don't know the answer for sure, doc. I do know that it was a priority with the C5 Corvette to be able to fit golfclubs in the back. I wouldn't be surprised if it was a prioirity in the XLR.
The tircky part will be the top. From what I've read the top takes up 60% of the trunk space when down. The trunk is 12 cubic feet in size, but I don't know the exact dimensions.
You have the correct price range.
The release date is commonly given as Spring 2004. I've seen a pre-production version on the road. I would guess that it is just around the corner. They may be trying to hit the market when the convertible weather is rolling in.