A month a go I bought a used car from a dealer. The dealer gave a written warranty for 'major mechanical failures.' The next morning I noticed the car was vibrating violently and was spewing out a lot of white smoke. Symptoms go away after the vehicle is driven for 15-20 mins.

I took it to a garage and I was told that the particulate filter and all its sensors and wiring have been removed from the car! What is my legal recourse?