EDIT: Information below is no longer valid as of November 2023, as the layout of this car park / its entrance has now changed.
My preference for parking when I visit Chadstone is Car Park C, what has often been known as the "Coles Car Park", this is accessible from Warrigal Road, via Middle Road and City Circuit.
It's my preference as I'm usually getting to Chadstone from the Monash Freeway, so am exiting onto Warrigal Road for Chadstone.
Currently there are building works and road works ongoing at Chadstone and will be for the next 6+ months moving forward.
At the moment all traffic on Middle Road is funnelled either left or right at the traffic light intersection, there is no forward traffic allowed.
If you're visiting Chadstone and intending to park in Car Park C; when turning onto Middle Road from Warrigal Road turn right from the farthest right of the right turning lanes and keep to that lane as you go around the corner. You'll be next to the median strip as you get onto Middle Road (and inevitably be sat waiting at the traffic lights).
First entrance, do not enter here, but exit here when you leave.
Turn right from the far right lane onto City Circuit. Don't be tempted to get into the left lane and do not try to enter the car park from the first entrance. That's what everyone tries to do.
Don't panic, it does look like the other entrance of Car Park C (there used to be two one after the other on City Circuit) is blocked, that's because it is.
One way road - City Circuit. Car park entrance is just after this bend.
Additionally the road becomes one way as it goes around the corner.
Follow City Circuit around the corner and there is a second entrance into Car Park C. Turn left here (around the road works barriers) and then immediately turn right and go up the ramp to level 3 of the car park.
It's generally not as busy up here because everyone goes in on the lower level, does several loops and then, and only after a few more loops do they get up to level 3.
Level 4 used to be accessible but has been blocked for building works.
Car Park C ramp to level 3.
Also, if you're driving a 4x4-type ute or SUV don't panic...too much, I drive a Ford Ranger and it fits into Car Park C. It doesn't look like it, especially when you're driving up the ramp and looking at the scratches on the roof, but it does. However always double check the height of your vehicle and the height of the car park (2.0 metres).
Note, when exiting do not go out the way you came in as that will deposit you back onto City Circuit and you can't go back around that one way section. Instead at the bottom of the ramp turn right, then left and then follow the car park around to right and then left you can exit, there's signs or you'll see cars coming in. This will let you exit out the first car park entrance, the one everyone was using to get into the car park. Then you can depart wherever from there.