Just thought I share my solution to check the coolant fluid level on a murky bottle.
1/ get yourself a PLASTIC Chinese style chopstick (not a pointed Japanese chopstick or a dirty one from the take away
2/ Cut off excess chopstick
3/ Cut/hacksaw a groove around (about 2cm) from bottom

The grove will help hold a small amount of coolant if at correct level

My Bongo has a handy little hole on the bracket......... perfect for holding the chop stick







