About 300,depends of style,is it C/P or brush...when I brush,It`s even more...
I have monitor size size 1280x800 like HUI,but my comp is not slow,so I can work with many layers...

pretty sure glac is the worst, he sometimes has 2 psd files for one chop as there's too much for one

im normally about 20, most ever was about 28
i do have more on my vexels though

Max. 50-60 but I`m not brushing every pixel in my works. I understand this as CAR thing not tehnique. So car is no.1 in works. If I can keep some part or borow it from another, why would I do 6 times longer thing?

But everybody has own style.

i have 353 layers for now on my new chop but i have alot more work until i'll be done with it

I used to merge after every layer was complete when i first started (was useless for when it came to changing things), but my cr-z chop at the moment is across 2 PSD's with 800+ layers on each. My computer is slow as hell though, so i needed the 2 PSD's
Its a bitch when it comes to trying to find a certain layer though, it came to a point that rather than find the layers for the hood, i'd print screen and copy/paste the the whole hood to change it.
I also started naming all my newer layers to help with the organisation, though I would merge more together if i didnt have so many with layer blending options on them.

When working with heaps of layers, the best thing to do is categorize them in folders and then label the folder. Grouping them like that is invaluable.

my current wip (which you know hui )
atm has layers for body, fill/quick selection layer/bg, original car and bg

my max is the ferrari with about 40 levs but 1 is enough, maybe i use very much dodge/burn that not work on a empty level

ctrl g FTW!

I don't know how you can work with so many layers,the most i have used was around 130-150 for my Ducati.Most of the times I'm using around 30-50.And I don't use that count becouse of PS or my pc,my pc can handle them,it's just easily for me to work.