[NZ_M3]

I've been told 6 years is the maximum you should leave the film on before it goes hard and becomes difficult to remove.

It comes down to how well the paint job was done in the first place that dictates if the film will remove paint with it.

You also peel the film off not against the paint, but rather along the paint - i.e. stretching the film so that it loses its ability to cling to the surface - allows for easy removal without resorting to heat (heat can damage paint also if not used correctly).