I have been doing quite a few welding repairs over the last while. I painted the various panels as I went along using custom aerosols. Actually the paint finish looks great. Handy way to do individual panel repairs without all the set up and clean up of compressor and gun. However it was very soft and didn’t seem to be drying properly even after a few weeks. I went back to the supplier who said ’ oh yes well that is a 2 pack acrylic in the aerosol but without the hardener’…gobsmacked 
Now I have recovered from the shock and reconciled myself to stripping it all off again I am going to repaint all the panels I repaired. Eventually I will also have to repair and repaint three of the doors ( bubbles of rust in bottom leading corner) and spot repair the boot/trunk lid.
I am going to use cellulose. I don’t have the breathing equipment for 2K.
Now my question- how much paint. I need enough to do the job in hand + enough to comfortably extend the new paint to the whole car later if needed and bank some for future repairs. I’d rather have a litre over than find myself short.
Nothing specific in the archives but best I can come up with from various web searches is 6 litres/ quarts for a total repaint.
What is your experience.
Cheers.
Dave.