The water and coolant is put in the coolant reservoir for the location of this refer to the owners manual. It is best to do this when the engine is cold otherwise you run the risk of getting boiling water all over you. the mixture of coolant to water should be about 50/50.
In the radiator
At the radiator or overflow tank. Do not add water, add coolant.
In the coolant reservoir in front of the engine.
The coolant for a BMW x5 is placed into the coolant overflow tank on the left side of the engine compartment. It should be filled to the full mark when the engine is at operating temperature.
To the left of the engine - in the coolant tank
On the right of the radiator or tlright in front of the intake filter tube there is black container with a cap, you add it there. Remember you must bleed the system
Yes
never in any car,water evaporates,causes rust and will run hot
water, anti freeze or coolant.
In a BMW, you typically add water to the windshield washer reservoir, which is usually located near the back of the engine bay and marked with a washer symbol. For coolant, you should locate the coolant reservoir, often a translucent plastic tank near the radiator, and fill it with a proper coolant mixture. Always ensure that the engine is cool before opening any reservoirs to avoid injury. Consult your owner's manual for specific locations and instructions for your model.
If there is no risk of freezing , but it will weaken the strength of the antifreeze / water coolant mixture
yes but i wouldn't if you live in a cold climate your block will freeze and then you lost a great car :)