Spacey, by the end panels I take it you mean where the rubber stoppers are on the foot and where the HDD rests?

They do come off easily, but there would be no way to put on the inside off the case to cover all the holes without actually having to void the warranty

only thing I could suggest and ive done it a couple times but its a pain, is taping the outside of the case, covering to airholes on the side and back, and power/av/hdmi/and stickers with tape and paint away, and when your finished take all the tape off, and if you're using spray paint spray a little in a cup and get a brush to fill in the areas where the tape was. This WILL ruin your brush though.

alot of effort to avoid voiding warranty, but yeh you are avoiding voiding the warranty so its all good, hope this helps :S