Does anyone know the part number for the thick rubber piece that sits inside the body panel collars that the bolts slide through? I have found the collar part number and assumed the rubber piece would come with it, but I guess it doesnt.

 

If you mean the sidecovers it is
921610685

I ordered 2 of the metal collars and got 1 collar & 1 rubber damper......

 

Thanks, that appears to be it.

 

You can also make some with different diameters of rubber hose.