Well I found that keeping the canvas bonnet tape dry and lining the bonnet edges with PTFE tape works the best of all. Clean the car tapes well to remove any lubricants and they will stay clean as its the grease/wax that holds the dirt which also acts as an abrasive when dirty. The PTFE tape is supper slippery and doesn't have a ridiculous level of adhesive backing so is easily removed if or when changing is required without leaving difficult glue on the bonnets. Although in all honesty I have never replaced the PTFE! not needed too!

This also works well on top of the foam seal around the heater box when applied to the top surface.