My 17 Mirage CVT has slowly worked a new bit into it's repertoire. There is now a very distinct low note resonance/droning vibration that can be heard and felt through the seats and steering.
In certain conditions.. while driving at any speed/w RPM between 1800 and 2100 while accelerating (as when cruise is adding power slowly) the rattle starts and will continue until engine load eases or rpm moves out of this zone.
I've been to dealer and took service tech out for a drive but no resolution in the works. Dealer has fixated on the exhaust resonance issue which Mitsu is aware of while ignoring the vibration and rattle I'm concerned about.
Oh well.. here we go again. 3 or 4 months of forcing dealer to properly diagnose and fix issue while I have to drive "the rattler" and put up with it.
SOLVED: loose exhaust hanger.