This is hard to answer without knowing what the factory finish is, lower end coaches will have fiberglass with gelcoat and vinyl graphics which are prone to cracking. Higher end coaches may have full body paint which tends to last longer, but also requires slightly different care when it comes to restoration.
There is not much you can do about vinyl stripes other than remove them, which in itself is a big chore, then replace them with either new vinyl or paint. Gel coat can be restored through buffing and polishing, this process removes the upper oxidized layer of the gel coat, then you can add a protectant. Gel coat tends to be much thicker than paint and clearcoat so is somewhat forgiving when it comes to using polishing compounds to remove the upper layer, though done wrong this can still destroy the finish on any vehicle. Restoration of full body paint is much more complicated and depends on how far gone it is.