That is true, ultimately, but it doesn't always go down like that.
I recently worked with two Mexican brothers, the younger one had no accent but was still noticeably brown. He was in college and was involved in the bro culture, so lots of partying. He told us about his car getting pulled over while he was driving his crew around, I forget exactly what was in the car but someone was holding something, if not everyone. The cop told him the car and everyone in it was getting searched. My friend told him to get a warrant. "Boy, I can get on the phone with the judge and get a warrant right now." "Good," he said, "do it."
The cop let them go. This was a Georgia cop versus a young chicano kid. If he could be successful, I imagine anyone has a shot; of course as you say, some cops will fuck you over regardless, but in that event it's gonna happen anyway, so you may as well try. The key, I think, was that the kid was steadfast–he knew he was right–and as respectful as possible.
also, @doctorow, I can't find the "bust card"