Unfortunately CPZ will not solve the problem if the intruder has paid to park in the Zone!
The law is the that exit from your drive should not be obstructed, however, blocking your access into the drive is just tough luck. The council will for approx £80.00 mark the access to your driveway with a white I----------I they say this does act as a detterant but again is not legally enforceable for entry.

I have had varying success with a polite note from screwed up and thrown at house to culprit apologising and moving on.

I have on occasion parked across the drive myself which surprisingly results in alternative parking slots being chosen.

I have a personal gripe that the Station car park Perry Vale is vastly underused due to cost. Surely a reduced price would see it fully used and the resulting revenues would be in excess of the current income for no additional outlay save for adjustment of the ticket machine....simple really 15 cars at £5 as opposed to 50cars at say £2.50/3.00 but what do I Know!!