The difference is that non-turbo C900's do not have a battery tray - the battery just sits on the body metalwork and is clamped directly to that with j-hooks. In the turbo C900's there is a special metal tray that lifts the battery up off the body metalwork.
This is the battery tray in my 8V turbo sedan (pic taken about 8 yrs ago):
For comparison, this is the engine bay of the 2.1 sedan I bought earlier this year with the battery removed (june 2019 pic) showing what no battery tray n/a cars are like in the same area:
I'm going to be giving the whole area a full treatment to get rid of that rusting and repaint with colour-matched aftermarket auto paint.