Just give us one of your tricks that may help someone else putting their car to sleep for its long winter nap.
Clean everything out of the interior that those little grey beasts can make a nest out of. Use heavy amounts of rubber lubricant on the rubber door seals then lower the windows about a quarter inch so it is not putting pressure on the rubber seal (especially the top corner). The seals are expensive and a bit of a job to replace. This certainly applies to C5's not sure about the other variants but it seems to work for my car.
Clean everything out of the interior that those little grey beasts can make a nest out of. Use heavy amounts of rubber lubricant on the rubber door seals then lower the windows about a quarter inch so it is not putting pressure on the rubber seal (especially the top corner). The seals are expensive and a bit of a job to replace. This certainly applies to C5's not sure about the other variants but it seems to work for my car.