A lawyer whose private practice is doing so poorly that he goes to extremes to cut costs (such as running his office out of his car or the local Starbux). These lawyers are not always incompetent (some may have experienced a stroke of bad luck).
The term originated from a misperception in the movie "The Lincoln Lawyer" that the protagonist, Mickey Haller, has to run his office out of his car. Although his clients are far from one-percenters, he appears to run a modestly successful law practice. The movie does not disclose why Haller prefers to use his car as his office.
The Hyper-Chicken lawyer in the Futurama episode "Insane in the Mainframe" is most likely a lincoln lawyer.
Judge: counselor, what evidence do you offer to support this new plea of insanity?
Chicken Lawyer: Well, for one, they done hired me to represent them.
:::Judge bangs gavel:::
Judge: Insanity plea is accepted!