I'd add the boot pop mod' to your car. Not only is it very cool but also (the main point for you) it adds much larger Pump Stops (these are also sprung) which will more than take up any play in the boot as they are adjustable. You could always just get the stops alone, swap them out and job done, takes about 2 minutes.
Boot Pop Kit Part Numbers2x Skoda Fabia Gas Struts
6Y0 827 550 C £35.98 inc Vat for the pair
2x Scirocco (sprung) Pump stops
1K8 827 761 D. £9.89 inc Vat for the pair. Bits that you need most!
2x Seat Leon Ball pins
1J6 827 439 A £11.97 inc Vat for the pair.
A "How to" guide on fitting the Boot Pop Kit (includes fitting bump stops).......
http://www.ecstuning.com/stage/edoc/MK5RearHatchPop.pdfIf you go for the Boot Pop it will need coding via VCDS afterwards to allow the mod' to work.
Hope this helps
In case you've not seen it.......