Even hooked up to a battery conditioning trickle charger in a well-ventilated garage, a car will inevitably deteriorate if left for long periods of time. The poorer the state of the fluids, the higher the rate of deterioration, so it should be fully serviced before being locked away. Basically you buy new to get a long warranty and, if you re-sell within four or five years, in exchange for heavy depreciation you may not have to spend anything on repairs and replacements. After five years old, the bill for repairs and replacements will gradually grow to the same as the depreciation, and will then increasingly exceed the depreciation. The only way to protect your investment is to buy an appreciating 'classic' in exceptional condition. But the problem with that is the classics that appreciate the most are the least practical to use. However, think along the lines of a perfect MGB, any you might come out smiling.