I used a radar detector both on car and motorbike. I got caught speeding on both
. I quit using it and paid attention to the speed limit, haven't got any speeding ticket.
I think having a radar detector only makes you brake the law, giving you the false impression that you can push the pedal as much as you want and never pay a speeding ticket. Bottom line, if you don't wanna get caught, drive according to roads sector speed limit