I've only been randomly pulled over once while I was on my P's. The cop had an MR2 & wanted to take a look as he was doing an engine conversion
Only other times were for defects (thrice I think). Unlucky those times, spotted by cops that were running low on their defect quota.
Been blocked off though. Mainly cos I was doing well over 200 (while street racing) & didn't stop. Long story but I absolutely deserved it. I actually have respect for police, he set me straight & I've been 100 x more mature ever since.
Actually...now I think of it there were a few more, but from memory I was young & dumb thinking a cop wouldn't chase me for valving him in the face.