I'd try to pull the plug. I've seen the coolant that came out of other cars from that part of the globe and it wasn't pretty. If it doesn't come out...
50mpg, running stock size fairly new winter lugs,sticky rear brakes, noisy front wheel bearings, driving into work 20 some km city/highway drive trip...
You can always drain, fill with distilled water and a little bit of coolant (100ml or so) and flush several times until the approximate water content...
Yes you gotta tighten the tension bolt bit should loosen the two nuts holding it place first. I wasn’t very clear and mentioned doing it with the car...