looking for 380/500sl seat belt holder

I saw recently that there was a clip or holder that put the seat belt for a 380sl in a place that is actually accessible... it was some sort
of plastic thing that went under the headrest, and brought the seatbelt out to where it is besides the seat, instead of behind it.
I am unable to locate it online. Can anyone give me a link for this accessory? I'm a new owner but this is becoming a very important addon!!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.