This is not a fStorm vs Corona post, fStorms tone mapper just look and behave better in my opinion.
I've been mimicking fStorms tone mapper with CameraRAW the past few weeks.
You can't over flatten your image with this tone mapper, and I think this is one of the main reasons people say fStorm feels like a camera.
If it looks like someone dropped a nuke in your scene when you are using 0.01, something is wrong with your light / exposure settings.
The Recipe* I use HC in Corona when I work. But when it's time to save, I switch to 1 HC (Linear)
* Open the 32bit .hdr/.exr in CameraRAW.
* Change Process to 2010, set Recovery to 35 and Contrast to -4.
It wont match fStorm 100%, but it's much closer than Corona HC. Download the .xmp and give it a try on your car render!
EDIT:
I have attached the .xmp settings file. Because CameraRAW has some weird default settings that need to be changed.
Just load the .xmp file here and everything will be good. 35 Recovery is max, so you can use anything from 0 - 35 Recovery.
1.75 HC in Corona is the closest we can get to max "0.01" in fStorm. But Corona boost the darks and don't have that sharp knee at the end of the curve.
1.75 HC Corona0.01 fStormComparison (Yellow is Corona, Blue is fStorm)