. I use PU foam which gradually forms an indentation which gently locates craft laterally and reduces some of vibration (noise) when towing. Sorry but posting has been erratic recently the system simply going dead on me. Left it a while and it now works. The only way I could post was to only send a full stop, which you will find at the start of this post!
Chamfered front ends and deformation can be seen. Ive perhaps used this method for collectively 5-8000 miles of towing.

Looks very nice and cosy Al!