Where do I mount this in my car?

Cup holders are the easiest spot. You can also hang it from air vents or place it on the dash if you secure it. Test the position before driving to make sure it won't slide around.

How long does the 18G gel last?

Gel fresheners typically go for several weeks to a couple months depending on cabin temperature and ventilation. Warmer cabins and running AC/heat will speed up scent release.

Will this spill if it tips over?

Gel formula won't spill like liquid air fresheners. If it tips, the gel stays contained — just set it upright again and you're good.