I would imagine 2 traffic coppers in a car can corroborate that they were doing 120 to maintain the distance between us even if they didn't really have me clocked at 99 though....
For me the trick is to be reasonable with a dollop of humble pie on top, and agree with them without admitting anything specific as I've been told many times about coppers attitude test when stopping someone will often determine how it plays out.
No one wants caught out but your right, they've got a job to do and without them it would be carnage out there