How did you know it's 2001's

model year of 2002 doesn't mean it has to be produced in 2002. It can be made during later year of 2001. Check with an authorized Lexus dealer with VIN before taking actions.

If it's indeed a 2001 car but sold to you as 2002, you have all the power to go after the dealer. It will not easily give you money back, you might have to twist their arms. Since the car is already 8 years old, it should be within the small claim limit. If you can handle it go for the claim court, otherwise, hire a lawyer (better hire one on fixed fees, not hourly based).