Well I would definatly start by doing a clay bar on the whole car.... just becareful.... it can take off paint if done too hard.

Could then try some Meguires precleaner-wax all over.... then some Meguires Gold Class wax.

That's assuming that it's not faded paint and just something covering it like a film or something... if it's actually faded paint.... other than a repaint... I know nothing that will repair that.