I thought the police and law enforcement can only prosecute you if they have a video/picture that clearly shows your number plate or some other definitive way to identify your vehicle? It's why I blur all number plates in my pictures that I post (both my car and others) so that's identity is that bit harder from a legal point of view.
But as with everything, not advisable to advertise law breaking so clearly. Better to say "was going a fair speed
" than clearly state your speed, despite the difference in speedometer readout and actually true speed (via GPS tracking) it'll still draw attention from the law.
We all like to put our foot down from time to time, just be careful when and where!