the maint. reqrd light comes on like every 5-6k miles to remind people to take their car back to the dealer and waste lots of money. You can turn the light off by... with key off,push and hold in the button on the gauge cluster that resets the milage,while holding it in,turn key on and wait about 15-20 seconds and the light will go out. release the botton and you good. As far as the white smoke coming from the rear probaly your exhaust,maybe you ran over some water causing a little steam. The sqeeling noise could be belts,brakes,etc. check to make sure your wheels are tight and the wheels covers are pressed on tight. I'm guessing that its something with the engine causing the sqeeling noise especially when you said the engine light comes on. Sounds to me like your paranoid because you had your tires put on by a non-caring mechanic,which tends to make a person notice more things wrong with their car.