It really depends on too many conditions to give you a simple answer.
The best way to determine what you'll be left with is to look at the door jams, or the underside of the hood. Basically, compare two areas close together, one that's seen the sun, and one that's always hidden.
Also, a good polish will get rid of 90% of fade, at least. The three step Meguiars is good, as is Zymol. Call a local auto detailer, get a quote and ask what they use. That way you can decide if its worth the elbow grease.
Anything will look better than a yellow stipe.
