My car's steering wheel wobbles when driving at slow speeds. It mostly smoothes out once going 40+ MPH. So, I do not think that it is because of a warped rotor. The car drives straight as long as the wheel is centered, and there are no vibrations, only the wobble. The car has about 180,000 miles on it. The tires are in pretty bad shape, so I am getting them replaced soon. If that doesn't solve the problem, what else could it be from?
The issue you are describing sounds like a bad tire. As weird as it sounds, sometimes problems with tires are more noticeable at low speeds. When you get the tires replaced, be sure to have them checked if the wheels are bent or damaged in any way, as that is another possible cause of this wobble. If the problem still exists after replacement of the tires, it is very likely a loose steering or suspension component, and should be looked at by a professional technician. They will be able to perform a complete safety inspection and advise you of any repairs that should be made.