I have a spoiler on my VT, wish it didn't but I don't want to take it off and have holes there.
Find a pic of a white VS like yours with a rear spoiler and ask in the photo shop part of the forum to make it black/grey to get a idea of what it looks like.
Spoilers on Commodores are useless in my opinion, all they do is add weight and don't look very good (unless its a lip spoiler and even then it doesnt suit most). A carbon fibre spoiler will still add weight, just slightly less and still not look good.
I couldn't imagine a carbon fibre spoiler being cheap, I would spend that money on suspension, brake, or drive train upgrades.
I got this from the ricer of the day thread, I have seen a lot worse but this looks as gay as the rest of them.
theres a photo on a different car guys, looking at the picture that fool doesnt know how to attach a universal spoiler anyway. i can get one the exact same for $289, but looking at your picture 2die a rear wing does not really look good on a commodore especially with the centred legs.