Here is the collection of  list of top 5 bumper stickers in Los Angeles. This is not just based on some guy's casual observation, this is data collected, collated and co-agulated through thousands of hours of cutting edge data-collection, collation, and co-agulation technologies

These are ranked by popularity

5) Calvin from Calvin and Hobbes pissing on something.

While it is common knowledge that it takes a certain kind of person to put a sticker of Calvin pissing on something on the back of your car, the history of this phenomenon is perhaps a little more elusive. It all began with Calvin pissing on a Ford sticker... or was it Chevy? No sooner than these stickers were the de-facto decal of Ford (or was it Chevy?) owners everywhere, the tables were turned and Calvin was pissing on the very symbol of the brand of truck that the original sticker owners drove. While this ingenious reversal of fortunes for Ford (or was it Chevy?) owners was perhaps forseeable, what followed was anything but. Calvin was soon pissing on anything: Mazda's, the Toronto Maple Leafs, the NDP, it just didn't matter anymore.

4) Anti-Bush Stickers. George, not Kate... I assume.

Although anti-Bush/War stickers are quite common across the US, Canada, and it seems Iran among other places, in California there seem to be more than usual.

Bush for Ex-President, "Bush" in a circle with a line through it, Bush Burned and Raped my Village, Bush Stole my Lunch Money, etc. Some are funny, some are annoying.

3) The Rodriguez Family.

These are basically collection of stick-man type stickers, each one representing each each member of the family, with the name of the family underneath. There are tons of these.

2) I Live Vicariously Through my Child stickers.

"My Child Was the Boner of the Month at Valley High" stickers.

"My dog is smarter than your honors student.

Depends on the student. Depends on the dog"

Most of them the stickers are quite vague and are about being a "superstar" or something similar.

Finally, THE most popular bumber sticker in the greater Los Angeles:

1) El Cuchy, 97.9 La Raza

This Spanish speaking station has also come up in this blog before. El Cucuy is the host.