Dashboard mount disc?

[Mag1calTrev0r]

Sorry if this has been covered before (I've searched honest!)

I'm after a simple plastic disc to be used for sticking my SatNav (Tomtom One XL) to the dashboard. I've seen them on ebay but only packs of three and they seemed to have a ridge around the edge which might not fit.

So I just need a very simple plastic disc with no ridge around it that I can stick to the dash.
Has anybody got any recommendations/links to any products?

Thanks