You guys are going to the wrong shops if you don't know about on car balancing. For on car balancing they use a machine which spins the wheel. They ensure that there is now wobble, shake, etc. in the steering wheel, etc. I will be honest that I have not paid a huge amount of attention to exactly what they do but it is like magic.

In my opinion if you are running a civic or something as a commuter car any tire shop should be fine. If you have a sports car and are spending the money on nice tires, modifying your car, etc have it done right. Especially considering that on car balancing does not cost any more.

Balancing on the car allows for correction of imbalance in the driveline, axles, brake rotors, etc. It's all done by adding weight to the wheel, but it does work, ONLY if the vibration is not caused by the tire/wheel.