How long does one brick last?

Gel bricks release scent gradually over weeks depending on cabin temperature and ventilation. Hotter cabins accelerate release. Replace when fragrance dims or the gel hardens completely.

Can I use this in a hot car without it melting?

Gel construction is heat-stable but designed for normal cabin conditions. In extreme summer heat, move it to a shadier spot (under the seat works) to slow evaporation and extend life.

Will this stain or damage my interior if it leaks?

Solid gel formula doesn't leak like liquid fresheners. If the brick breaks or cracks from extreme pressure, wipe the residue with a dry cloth — gel won't stain upholstery or plastic.