For a couple of months I was loosing coolant but never saw a leak.

I finally found a pinhole leak in the heater hose near the firewall. Not enough to ever see any coolant, but it stained the gearbox rust colored. So I cut off 3cm of bad heater hose end and put it back on the head. Leak fixed. I took my 1200 on a 1200km trip and it didn't lose a drop of coolant. After sitting overnight, I loosened the cap and it still had a bit of pressure in it!

I had same if you remember in my sedan and I got radiator rodded and a new cap. The coolant loss was minimal but I also noticed staining on my starter motor.
Went through efforts of Bonnet vent (which did reduce under bonnet temps) and shrouding radiator from the front to force air through rad only)
Ended.up being heater core had leak that ended up filling,my foot well.

Small things are amazing how big an impact they can have