[MetroMPG]

I used a hot glue gun.

I broke the magnets into smaller chunks mostly to increase the number of attachment points and spread them around the wheel. Plus smaller magnets are more likely to stay attached to the disc when pulling it off the wheel, rather than breaking the glue.

I wonder, though... do two halves of a magnet, separated, have the same magical stickiness as a whole one? Hmm...