Trunk mat material? Ideas?

Would like to put down some sound deadener and cover it with trunk mat material over the rear end hump in my 67 Dart convertible. Thinking of using the sliver stuff from home depot/menards then putting trunk mat over it. Is there someplace I can buy bulk trunk mat material that would match the repro trunk mat I have in the rest of the trunk(herringbone design)? With the top up I get road noise from this area. Any ideas or thoughts? would like to see how others have finished their trunks.
Thanks
Aaron