No.
Assuming that the parking lot is exposed to the street, there is absolutely nothing wrong with posting an officer in or near the lot and recording the plates of vehicles that travel near the area. The notion that it is 100% okay that things that happen in public view may be subject to notice and recording at any time is very important to preserve.
Where this goes oh so wrong is when the PD posts a robot policeman [0] at the location, or a network of them throughout the district that record things (like license plates).
There are only so many officers in a district, each of them can only be doing one thing at a time, and every one of them requires OT pay for extended work hours. This means that a district has to decide if plate collection at a location is the best thing that they can be doing with a particular officer.
If a district can suddenly -for the price of one meatbag officer- dedicate ten new robot "officers" [1] to the task of car movement surveillance, then their powers have been greatly expanded.
It's very important that we protect the right to notice and record things that happen in public. I feel that it's equally important that we work to limit the damage that an entity can do when they have the resources available to record such things on a large scale.
[0] AKA: a camera
[1] who can work 24/7 and never require OT pay