Does it have a demo mode?
With TOM TOM you have a demo mode and if there are speed camera's on the route you plotted it
shows them up and the warnings etc....
There commer seperated data.
So they will store in sequence
Grid ref, speed, type of camera, etc...
With Tom Tom these CSV files are actualy POI - Points of Intrest.
I really dont know on the Street Pilot,
but there has to be some simularity's.
Try a google search for installing CSV files.
Let us know how you get on