Distilled White Vinegar will work
Use it with with a dilution of water.
If that doesn't work you will need to take an abrasive (IE: polish) to the car to remove them.
Do not let the water spots sit on the car for to long because they will damage the paint (Kind of like bird droppings but not as fast
)
Good Luck! BTW, the vinegar probably caught you off guard and you are nervous. I use to be a mobile detailer. I used the vinegar trick on many different exotic cars....you will be fine