Before you buy at least check out
www.cocomats.com
They are the original maker used by Porsche, MG, MB and others as an optional upgrade in the late 50' and 60's. They have mats for the cargo area. Natural rubber lined, 3/4 inch thick. Any grit or hair from a little monster (dog) holds tight and doesn't go sliding or flying around. You will need to let them air if really wet, that might be a consideration.
I like 'em. Some others here don't. If you get the right color, I think they are the best you could want.
Here's a pic of mine, they look much better in person, the colors match the interior colors.