I remember you mentioning early on in your posting that you had symptoms come on after being in the car (which you are in a lot during the day).

This might indicate some sort of compression in the lower spine. Does it go away after you get out and walk around? Is it more like the tingling one gets when an arm or leg falls asleep? If so, then it might even be a vascular thing...especially if it goes away right after you get up and restore better blood flow.