Those things don't just drop off - they are a bitch to get off the bumper. Some scum nicked it mate. You can still get them from dealers - a mate of mine got one recently, but there are loads of Cupra's and FR's being broken up for parts on ebay. Get one there that might even be the right colour.
 
I bought one few weeks ago for my facelift kit, if you let me know if its front or rear I'll give you the part number and the price from the dealer :)

I think its rear cause the front ones are bolt hole covers?
 
Rear tow eye cover

£4.83 + VAT comes in grey primer

Part no: 1m6 807 928 b gru

Thats the part number for my facelift rear bumper tow eye cover. I think its same bumper as a FR?