The cargo net that BMW lists for the 2 Series (51-47-9-410-838) does
NOT work on the M2C. It's square, and due to the offset tiedown points in the trunk, you need one that looks more like an inverted triangle with the point cut off.
I picked this one up on Amazon for $15. It's a *perfect* fit-- it's identical in build quality to the BMW version, but the correct shape.
It works great-- especially since "Honey, can you go get a few things at the grocery store for me?" tends to turn into "Sure..... oh, look-- twisty roads, I'll be back in two hours!"
http://amazon.com/gp/product/B00TD3U...?ie=UTF8&psc=1
Oh-- the 2 Series mat in the picture (51-47-2-357-214)? It's a *perfect* fit for the M2C.