you can fit a cupra bumper, but you will need the lower bumper supports as they are different to the FR ones. As has been said its much easier and cheaper to buy a rieger rear diffuser and fit that to the FR bumper, and as has already been said (but you missed....) they come in either single exit left, right OR BOTH, twin exit left or right and even central exit if you are having a custom backbox. loads of options, look on their website