netting on back of seat
 

My netting is all loose. Is there a way to tighten it so it hugs the seat once again?

I want to say that they can only be replaced (I'm sure it can be rigged, but that's your decision). I want to say hatterasguy did this project not too long ago, so he could probably help you out there.

About all you can do is double up the top cord until it's tight and then sew it together with matching color thread. That will at least keep the top tight. Not great but cheap and quick.

If the netting is like that in my previous 300E, you can remove the plastic rails at the sides and tighten (shorten) the top string. This will help keep the top tight, as mentioned, and will improve the look of it. I think that past a certain stage, the netting material just loses its elasticity and that's that (unless you replace all of it).

I fixed the nets in my W126 by removing the plastic side rails as indicated above, then purchasing $2 worth of black elastic cord readily available from the sewing section at Wal-Mart, from fabric stores, etc. Took about an hour and the nets look like new!

I got this problem too. What a shame of MB to put such cheap feature in $50K and above cars like my 1989 300CE. A few years later the 300CE or perhaps other W124 got decent pockets instead of the nets.