Unless you are going for OEM production correct for judging or similar, from my experiences of that hard rubber liner collecting moisture under it from temperature swings, you would be much better off with some auto-grade black loop pile trunk carpet as the New Yorkers came with. On my '70 Monaco Brougham (which came with black carpet in the trunk and a matching spare tire cover), never did find any moisture under that carpet.
FWIW,
CBODY67