Buttercup? Really?
Hmmmm … regional car accessorization trends …
Orlando – Puerto Rican flags
Boulder – large collections of progressive liberal and/or Wiccan bumper stickers (“Visualize World Peace,” “TOWANDA!”, “FREE LEONARD PELTIER!”, “The Goddess is Alive and Magic is Afoot,” etc.)
Denver – ski rack, mountain bike, or kayak, regardless of season
Buffalo – either Catholic paraphernalia (rosary beads, medallions, saint cards, etc.) or … drumroll place …
CROWN AIR FRESHENERS!
You do know that each crown signifies a person the driver has shot and killed, don’t you? 
Our county cops have gotten a bug up their ass about anything hanging from a rear view mirror. Anything. They’ll pull over anyone, for hanging anything. Former babysitter got pulled over for fuzzy dice. Neice got pulled over for graduation tassel. Mom got pulled over for a PTAF. Nephew got pulled over for a prom garter. All the above within the last two weeks. Sometimes they ticket, and sometimes they don’t. Mom got a ticket, but the neice and nephew just got a warning, so it’s not like they’re targeting anyone. (Mom is 70, and the neice and nephew are both 18.) Needless to say, nobody has much of anything hanging from the mirror around here anymore.
Harumph! And it’s about time. It is illegal, you know.
elmwood: if you’re lucky enough to be in Boulder, don’t complain about the bumper stickers. Go climb the flatirons or smoke pot with the cops on pearl street. Or go eat at The Sink, where all the tables have articles from The Onion all over them. Geez, I miss Boulder. Road trip this summer baby!
In my car it’s a red plastic lei(sp? the hawaiian thing) that I found by the side of the road. It just belongs on my rearview, and I would be pissed if a cop called me on it.
LC
Uh, “Emergency Condoms”? Hanging from the rear-view mirror?
<bowing towards Zette>
Nope. 
Sorry to burst your bubble, but it’s Buttercup (the green one) from Power Puff Girls.
I have a dream catcher hanging from mine, that way if I ever fall asleep while in my car I can retrieve the dream I had and see if the resulting wreck was worth it.
on a different but not worthy of a new thread note…how about a flag, an american flag, about 18" tall and 2’ long, DEAD FUCKING CENTER IN THE REAR WINDOW! I guess even the mentally deficient can be patriotic and get a license.
What you need is one of those minature straw brooms with the little tag on it that says: “Alternate form of transportation.”
All my Pagan friends have those.
Hilarious- whenever I see dreamcatchers hanging in cars, I say the exact same thing. I guess great/twisted minds think alike!
Zette
A cop friend of mine told me that there’s a bit of an Urban Legend going around that CDs are supposed to mess around with radar guns.
She laughs her ass off whenever she pulls them over for speeding, and they ask her how they were caught with the CD hanging from their rear view.
When I first read the OP, I almost posted to say that I often mistake flashing crystals for police lights. But I thought it was just me. Thanks, gato, I guess I’m not as paranoid as I thought.
[sub]Or at least there’s someone else as paranoid as me…[/sub]
Just because you’re paranoid doesn’t mean they’re NOT out to get you…remember that.
Zette
I had something similar up once: a stuffed dragon from IKEA that I gagged, blindfolded, and hogtied. His eyes were open really wide and rolled to the left, so he looked really terrified. At first I hung it in co-workers cabinets at work, but then I put him on my rearview. Unfortunately, last winter someone shot up my ride (who shoots the window out of an 89 Oldsmobile Grande Royale? Obviously I’m poor, people, or I’d at least be driving a car from this decade that does NOT comfortably seat seven and require a special parking permit) and stole him. Yes, I am as amazed as you are.
Currently, I have a Sunflower air freshener from Yankee Candle Company; a cool silver-plated bookmark with a quote from George Sand: “It is never too late to be who you might have been”; and a little clay jug hung from hemp that holds scented oil.
Also, because of the massive width of my dash, I have a variety of small toys hot-glued to it. I hope that’s not illegal.
As for the crystals, I have a friend who regularly converses with her crystal (they’ve worked out a code). When I pointed out the fact that it blinds other drivers, she just said, “I need to have it close so I can hear it when it starts to talk,” like I was the dumbest person ever.