Sadly it rarely lasts, and all but the most fastidiously-maintained vehicles will soon pick up scratches and stone chips. You can keep touching up the blemishes and polishing to your heart's content but it's often a losing battle.
What if you didn't have to bother?
Self-healing polymers may be the answer. Materials containing the polymers can effectively heal themselves, and in a remarkably short space of time. Surface scratches can disappear in the space of only 60 seconds, meaning an automotive paint containing such polymers can forever keep the lustrous shine from the day it was bought.
The material, which is typically rigid, breaks down at a microscopic level when exposed to UV light, and in the process of melting down, fills any imperfections in the surface. When the light is removed it hardens again and you're left with an unblemished finish.
You can watch a video demonstrating the polymer here:
We're certainly looking forward to the day where an individual clumsily brushing past your car in a parking lot no longer results in unsightly scratches.
The car detailing industry might not be so keen on the idea though...