Getting values from a constraint

Hey all,
Imagine a scene where you (the camera) are on the side of the road and a car drives by from left to right. Following the car with the camera as it drives by is easily done with a “Track To” constraint. However, I cannot seem to find how to get the actual values of the cameras rotation from the constraint. For example, at frame 100 what are the actual XYZ rotation values of the camera that the “Track To” has rotated it to?

The reason behind the question is after a certain point, I want the turn the “Track To” influence to zero (0) and have the camera keep pointing to where the “Track To” had it. By setting the “Track To” influence to zero the camera snaps back to where it was pointing before.

Any ideas?

----- Ed