Best way to scent a car?

[ecnal]

Alright. I've tried the little trees. And the little candles. And anything else that hangs from the mirror, sticks to the window, or clips on the vent. I've tried the cans of gel. And the powders. And sprays.

They all work for a little while. A week, maybe. The ones than hang from the mirror bother me because they're always swaying around in my peripheral vision.

Some just smell like crap. But nothing lasts.

So here's what I'm thinking: those timemist things (http://www.timemist.com) in a car. Hooked up to spray maybe every 30 minutes when the car is running. Maybe just once when the doors unlock via remote? I don't know.

What's the best product you've found?