Ringing noise from engine compartment !

[CrankyOldMan]

<engineer_rant>
The reality of putting a dynamic system like an automobile into motion is that there will be resonant frequencies present for all components. Engineers do what they can to isolate and reduce them, but it's inevitable. One of the reasons that a $50k car costs what it does, is the money sunk into development and re-engineering. Making physical parts isn't cheap. Altering a $120k plastic mold die to compensate for harmonic vibration isn't cheap. Using materials that mate silently and resist squeaking/pinging/popping when flexing or vibrating isn't cheap. The Yaris does an admiral job of being relatively quiet for a sub $13k econobox. Expecting fit and finish on par with a luxury/exotic car is expecting more than the pricetag entitles you to.
</engineer_rant>