If you're too lazy to clean them I guess it would work

Now Ive heard everything

Sure. If you do, there'll be no need to 'flame polish' them down the road because the mylar takes the abrasion instead of the plastic. Put some on the side walls too, where the ball transmits a lot of energy in a curve.

In 10 years, pull the mylar and the ramps will still be pristine.

I probably wouldn't cover a decal with it, but they are usually on the bottom side anyway.

If you really want to go crazy, you could also throw some mylar on metal ramps & walls to avoid the very noticeable worn/scratched areas where the ball travels. On brushed stainless ramps this isn't that important since you can always regrain them, but it would definitely keep plated ramps looking pristine.

Good idea, and as an example I used the blood spattered ones from Pingraffix on TWD....Ramps are like new with tons of play.

Takes me just a few minutes to do and is easier than flame polishing, which does make the plastic softer, and easier to get a trail.

No harm to do....IMO, and when removed later, the reward is easy to see.