Yeah, but spoofing GPS is possible. The black box insurance gadgets typically wire directly into a car, so it'll be harder send fake data from that pipeline, but totally possible.

The benefit would come from smoothing extremes. Lie about speeds over 80, reduce big accelerations and hard breaking. Lieing about total miles could also work, but I think that could be done by just unplugging the box, or only sending it power and not data.