I am prepping the Z-car for winter storage. I have drained the water from the radiator and the block, and am wondering if it's better to leave the system empty or fill it with a 1/2 - 1/2 mixture of coolant and water. One thing I have noticed is that despite using water conditioners I have been seeing rust develop on the iron parts (water pump impeller for example). and the water I have drained us pretty red. I don't know if being immersed in coolant over winter would help this, or make things worse...??

The arguement against filling the car with coolant is partly enviromental and the PITA factor.... not that it compares to the countless other hours spent in the pursuit of last place.

What would you do? This car will be stored outdoors in the WNC - sustained winter temps as low as 10 degrees.