During my time in the RE's Airfield Repair Sqns we used to rotate our large stock of plant vehicles.
For this we installed vehicles into a large tailor made rubber bag, fitted dehumidifier and left it alone for up to 7 years that I know of.
Prior to this each vehicle was fully serviced, painted if required, batteries removed and stored, sharp edges padded, diesel vehicles fully fueled, petrol vehicles drained, vehicle driven onto insulated hard standing and mounted on axle stands then bag fitted and sealed.
Now I do know that the Diesel fuel may no longer be suitable for long term storage, but have all the Hydraulics, Brakes, Gearbox oils etc all been made unsuitable as well?