How long does one brick last?

Melon scent holds strong for several weeks depending on cabin temperature and ventilation. Warmer cars and open windows speed up evaporation; sealed cabins extend the life. Replace when you notice the scent fading.

Can I hang this from my rearview mirror?

Yes—the brick format works with any hanging method. If you need string or a clip, source those separately; the brick itself is the product. Most drivers wedge it under a seat or toss it loose on the passenger floor for discreet odor control.

Will this leave stains or residue on my dash or upholstery?

No. Solid brick format doesn't leak, sweat, or stain. Just avoid setting it where direct sunlight will cook it down faster than normal. Works clean on fabric, vinyl, or plastic.