Half of your advice is sound advice. Don't rely on Google maps, because they do not always source data instantly from Waze reporters. Use an app called highway radar, it pulls data from Waze, but also flight radar 24 to catch police clocking you from the air. Sometimes cops use laser and the only best defense against that is a AL priority system. Install a CB radio, and monitor truck frequencies. I use a uniden R7 for Ka band radar detection. The last bit of advice is don't speed alone, have someone with you with a pair of binoculars to scan the road ahead. Speed limits are mere suggestions for me in my GT500, I have not received a ticket with it or any of my other cars.
You can speed if you know how to avoid cops or have the money for a lawyer. I've been caught doing almost triple the speed limit and my lawyer was able to get me off with 4 hours of community service, no fine, no points.
Waze can be a very useful app for this. I've got a pretty fast car. I try to pick the places I speed very carefully like a long entry ramp for a major highway. You can do a hard pull there without getting caught.
Waze is great, however the police have Waze to and they setup fake police locations to slow traffic down. So you can't always trust Waze, but if you combo it up with a good detector and laser jammer, you're much safer to disregard false waze flags.
