Soft floor coverings for my bunnies shed

My 2 buns live in their purpose built rabbit house & have grass time every day. As Gilbert my boy is a Rex I want him to have soft areas in the shed so his feet stay in good condition. So far the only thing he or his girlfriend will accept as OK to rest on are carpet off cuts. I've tried introducing mats, fleece blankets etc but they always end up bundled up, kicked away & nibbled on. Today in my ongoing quest to improve my buns living conditions I presented them with some gorgeous, new, Dry Bed - similar to Vet Bed, as suggested on one of the RU threads I had read.
Well you'd think I was the worst Bunny Mummy in the world! Lots of chewing & scratching it. They had to be rid of it ASAP! Now I know rabbits don't like change & this is a new thing but my 2 are very curious, they accept new food items easily, enjoy new toys etc so why is a soft place to rest on & take the pressure off their hocks so hard to accept? Any suggestions gratefully accepted Ideally I'd like them to accept the Dry Bed so maybe leaving it in their until its no longer new may be all it takes.

Oh dear, naughty buns!

I can't think of anything to suggest that you haven't tried already - hopefully someone else will have a suggestion for you

Ours dug at the vet bed we put in for a couple of days and pretty much got used to it now. They still dig a bit, but I got some velcro, stapled one bit to the underside of the vetbed and fixed the other side to the hutch floor - they can't move it now

I put some of the childrens floor tiles down (jigsaw type) which are a bit softer on their tootsies.

Thanks for the foam tile & velcro suggestions. I know the tiles you mean - I remember them from when I lived in the UK. We don't have them here unfortunately but will keep my eyes peeled for something similar.
In the mean time they continue to attack the drybed! What brats! We have had a near monsoon for the last 10 days. So exercise time has had to be indoors or on the deck which is covered as I don't want my Rexy boy getting wet feet. So no outside time has meant grumpy bunnies. :?