VTR registration question, what is a driver?

[pethier@isd.net]

I'm trying to fill out my VTR registration today for Rockford.

Is there an echo in here?  :-)

I'm confused about charges for extra drivers, and what is a driver?

My wife and I are going to the convention, with no other people.  I will be
driving at the autocross.  

How do we determine whether Sue is a "a driver"?
How do we determine whether we need to pay extra for a driver or a
non-driver?

There is something about the price structure that was either not
thought-out or is inadequately explained.