Robert Kearns (Greg Kinnear) gets an idea for intermittant windshield washers, shows the prototype to Ford, Ford steals his idea.
Luckily Kearns has gotten four patents on the technology, and hires Alan Alda to sue Ford.
After a lot of stalling Ford finally offers a $250,000 settlement. By this time Kearns is mad-as-hell and won't settle for money; he wants to go to court to force Ford to admit they stole his idea.
Twelve years go by. Alda quits. Kearns' wife leaves him. Patent law changes, making it easier to sue large corporations. Finally Kearns has his day in court, representing himself. He wins, and the jury awards him $10,100,000.
It's a rather small story to base a movie on, and there isn't much else going on here.