[Starter986]

Same thing had happened to me... after some spirited driving. It burped. I had the same trail of coolant.

Added distilled water to bring it to level... opened the vent to allow the system air to escape (for a few days). Paid attention to the level... hasn't happened since.

IMHO... if you found no wet in the trunk... leave the coolant tank alone.

Likely just a one-off. Surely a real pro will chime in.