Need advice on sub box build

[Redog]

Not really a sub box, but it falls in those lines.

I'm redoing on air horn and I'm going to be wrapping the base in trunk carpet. I picked up a piece from a 2003 Caddie at the junkyard. It was on the trunk lid, but it was the only GM trunk carpet I could find that wasn't soaked and the trunk wasn't opened.

Anywaywhat is the best way to wrap the carpet around the corners of the wood base? I was just going to strech it and staple it down with an industral staple tack hammer. I'm only doing one side of the wood