Vent clip vs. hanging tree vs. wood diffuser — which is best?

Vent clips give you the most scent control (most have a slider) and the strongest projection because airflow drives the fragrance. Hanging cardboard trees are the cheapest per car and have the most cult-favorite scent options, but fade fastest. Wood and stone diffusers look the nicest and project a more subtle, perfume-like scent, but specialist communities consistently note they don't last as long as the marketing implies.