Front flaps are the same, I'm using the Citigo ones on my up! As far as I can tell the rear ones will also fit, they are however shorter than the VW ones. I bought both sets as I didn't realise installing the Skoda ones involved drilling several holes in the rear bumper. Although they may well be easier to fit than the VW ones. As the clips that hold the rear VW flaps in place are a bitch to fit. Installing either set will involve damage to the rear bumper although the flaps will cover this.
Thanks again for your replies. I like the look of rear flaps even if they don't do much in the way of protection. I will still be putting them. Part numbers for Up and Citigo rear flap are the same apart from an 'A' at the end of one of them so they appear to be the same if not very similar. Just need to wait for the car to arrive now. Being built next week