i had vibrating problems with my hyundai it turned out to be i needed new tires the wights were gone. as for brakes since it is new it couldn't be your brake pads, i know that my brakes squeak every once and a while when there wet but it goes away. your car should be still covered on warranty...
I am looking for a new (to me) car and am quite interested in the 2006 and newer Sonatas. I'm looking for opinions on them- what do you like or not like about them? Does anyone know of any good sites where drivers rate them? Thanks!