I think it would look great!! I am considering one on my Mini One (when it arrives...). Have just found this normal Cooper S spoiler on eBay for sale.
http://www.ebay.co.uk/itm/BRAND-NEW...arts_Vehicles_CarParts_SM&hash=item43d17d70bc
http://www.ebay.co.uk/itm/BRAND-NEW...arts_Vehicles_CarParts_SM&hash=item43d17d70bc