A collective of inmates aligned along white racial lines, typically referring to racial alignment within state or federal prison systems (and sometimes county jails).
The biggest jerks on the road, most of the time if somebody cuts you off, speeds, gets too close, or is an all around jerkish driver, they will most likely be in a white car.
A dirty white hatchback car like a clio. It has writing on the roof and/or window, dodgy seatbelts, immobilser, windows and a cracked or missing bumper. Has car accessories/immobiliser in every window obstructing drivers view.
One of the hottest search terms on Google during April 2010. Apparently using Google to search this term would result in Google suggesting "Do you mean black people stole my car?" This has now been fixed by Google to not display this particular suggestion.
Originally the phrase was used by spammers and malware sites - clicking on many of the sites that come up for this search term will infect the users machine.