Re: cruise control surges
It depends, could be a 'burp' in the cruise control system due to the age of the car, could be the wiring, could be the cable... it's really hard to say here, but 2mph is quite a bit to be honest.
I test my cruise control from time to time when I'm on the freeway, it fluctuates a little bit but not by too much though... not exactly sure what your situation is like. =/
Maybe a quick video will help?