I'd start with the tires. A belt is most likely to break when the tread is just about completely worn out but it can happen anytime. If it's bad enough you'll see the steering wheel shimmy at real low speeds like when driving through a parking lot. You may feel the corner of the car going up and down too.
Jack the car up and support the front on jack stands, then run it in gear. One wheel will spin fastest. Watch the tire and the wheel from in front of the car to look for waves or humps in the tire tread, and watch the edge of the wheel where the weights clip on to see if it's moving left and right as it rotates.
Block that wheel with a long 2" x 4" to make the other wheel spin and check that one the same way. Be careful with that block of wood because the tire can shoot it out if it's laying flat on the ground.
If the wheel is moving sideways it could be bent or there could be debris stuck between it and the brake rotor. Cast wheels usually break instead of bending if they hit something hard enough. If they are corroding, some of it will turn to powder and that's what often sticks to the hub. Rust and scale can get stuck between the rotor and hub too, especially when you remove a rotor to replace a wheel bearing. This is a big problem with GM cars but it can happen on any brand. There's an access hole in the hub and salt and water splash in there and cause a round spot of rust to form on the rotor. That has to be scraped off before the rotor is machined or before it is reinstalled. If the rotor is installed in a different orientation that rust spot will prevent the rotor from sitting flat on the hub and that will also make the wheel wobble. Steel wheels can be bent by some older tire machines.
If a rotor is warped the most common cause is failure to use a click-type torque wrench on the lug nuts. Most Chryslers call for 95 foot-pounds but it may be less with cast wheels. Besides the correct tightness to prevent damaging parts, all the nuts must be the same to avoid uneven clamping forces on the wheel and rotor. With heating and cooling cycles the uneven tightness puts uneven stress on the rotor causing it to warp.
If you only feel the vibration at lower speeds up to about 35 mph and under moderate acceleration, suspect a worn inner cv joint.
Wednesday, April 3rd, 2013 AT 4:50 AM