Another thought on my declattered car & it has to be said that the declatteration is a side effect of other things which when you sum those parts,lead to a general quieting. I have gas struts on both bonnet & boot, on the bonnet because I hate stays & on the boot because of the spoiler & sagging hinge springs. These exert a constant force & that tension subdues panel resonances, not only with the lids but they act against the fixing points on the tub, rear wing panels & front wings.
Anyway you asked about how I made the packer for the snorkel.
I have a routine running constantly in my head which when seeing something interesting asks;
“can I use it?”
“Is it free?
Yes
Grab it
If no
“Is it cheap?
If yes
“buy it”
If no
“I didn’t want it anyway”.
This packing was cheap & it’s probably available on eBay.
It’s self adhesive, has a graticule on the back, which makes for easy registration before cutting & if you are joining it either at right angles or end on doesn’t tend to creep, although I tend to be generous at those points. On the snorkel picture you can just make out the foam being squished out indicating a good seal.
M