Adam Levine is taking a car dealer to court who sold him an extremely rare car, or so he thought -- because Adam claims he's been swindled.
According to legal docs, obtained by TMZ, the singer's going after classic car dealer Rick Cole, claiming they did a vehicle swap back in 2021 ... giving Cole a 1968 and 1972 Ferrari he says were valued at $950K combined and getting a $100K and a 1971 Maserati Ghibli 4.9 Liter Spyder in return.
The real deal could fetch around $1 mil, since only 25 were made ... the docs call it an "extremely desirable and valuable car in the current classic car market."
According to the lawsuit, when the whip was taken to Autosport Designs to market it, it turned out the Maserati wasn't legit ... claiming Cole took several steps to pass it off as the real McCoy after a failed auction of the same vehicle back in 2015.
Adam says Cole -- who's made deals in the past with Steve McQueen, Robin Williams, Frank Sinatra, and Johnny Carson -- kept all those earlier issues under wraps on purpose to make a serious profit.
The Maroon 5 frontman's trust is now seeking more than $850K in damages.
We contacted Cole ... so far, no word back.