All good advice to some degree but really the best thing to do with an unused car is to use it:-) As they say use it or lose it:-) Simply get someone to run it to operating temp exercising the auto/clutch, the pwr steering (if fitted) & the brakes. Also the heater & A/C system. A tank of gas is a cheap cost.Starting it for a couple of mins only every now & then is not good enuf, must be brought up to operating temp.
For extreme long term storage there's various inhibitors commercially available for the eng & cooling system. On jacks & battery removed.
There is another way out of this...........sell it !
Wmk2