One neat way to preserve your chassis is by not using it!

The other is to purchase some Sticky Teflon Tape, looks like contact but much thicker.

Made by ( and available locally! ) Associated & Tamiya. So should be easy enough to procure. Cost is less than $20.

Also a thin bead of C/A along the edges will help to preserve your chassis from the side impacts a little.

Cheers.