Excluding the dealership where can I buy rear spoiler for my xB? And how much?

you could check ebay or check out the reviews section on this site.
New Spoilers from the dealer will be order to match your color. So at least you don't have to worry about that.
But the ones on Ebay are way less.

Good luck!

I bought mine at the dealership but installed it myself and saved the $100 installation charge they were going to stick me with. It is not hard at all to put on, especially if you get it from the dealership where it comes with step by step instructions and installation templates for where to drill the holes. Ever since I have installed my spoiler it seems like xBs without them look naked.

moved...

What was the cost of the spoiler at the Dealership? Thanks.

put in a WTB (want to buy) ad in classifieds...i got a bsp color matched wing for my 05 xB for ......$75 and installed it myself. good deal eh? :)

~tesh