Will these clips work on all dashboard vent types?

They're designed for standard horizontal vent slats found on most vehicles. Before ordering, check that your vents have exposed slats you can grip from the outside — if your vents are recessed or have a different design, test-fit first.

How long does the scent last?

That depends on your climate and how often your cabin fan runs. The cartridge is not user-replaceable, so once it fades, you'll need a fresh unit.

Can I remove and reinstall these without damaging anything?

Yes. The clip design is reusable — no adhesive, no fasteners. You can move them between vehicles or reposition them inside the same car as many times as you need.