SpongeBob SquarePants sitting atop my air cleaner lid

The white stuff wipes off on the hood before the sponge ever gets squished. In the first foto you can see after closing the hood, the white soap is untouched. In the second foto, the soap is stuck on the hood insulation. So now I know the clearance is between the thickness of the orange sponge and the two sponges stacked together. By fine tuning the sponges, I can get an exact measurement, just as accurate as any other method if you ask me (OK plus or minus 1/8", let's say). The sponges keep you from damaging anything in the process.

This whole exercise is just to show what can be done when you don't feel like making a 20 mile round-trip to the store for putty/clay.