I agree with DM you can't put more than one layer of wax on as the new layer removes the old, but what wax also does is impart a gloss or wet look to the paint which is something you can't get with polish alone, so whilst you have a nice shiny surface after polishing it has no depth or gloss to it.
Clean then polish it to get the required finish, then wax or seal it to add protection and a wet look. Most sealants won't give a wet look, you need wax for that.
I normally stay away from this part of the forum as while i can admire the dedication and OCD levels of patience involved the BS side of it annoys me but that's more about the products and use of a thesarus to try and distance 'detailing' from valeting but FWIW...
There's no wax or sealant on that, i know because i was one of several people that put in 30+ hours straight to get it finished in time and was in the workshop with the owner colour sanding the bare shell at stupid o'clock in the morning 3 days before that pic was taken! When we were done the painter then attacked it with Farcela and 3M compounds while we got on other stuff. It's shiney because the paint is straight and totally free of orange peel/blemishes/swirls/holograms. As said wax or a sealant will add some protection and slightly alter the way light's reflected as the light has to pass through whatever is applied over the paint. IMO this is where detailing can be likened to audophiles... the differences can be as much psychological as real i.e. you've spent time/money expecting an improvement and so you see/hear one
I know this is cheating slightly as it's not painted but here's the ally fuel tank i made for it...
Pretty much the same deal as with polishing paint (except that paint is thinner and so easier to polish through)... very generally select an abrasive coarse enough to remove the scratches and then do it again using progressively finer abrasives until the scratches are too small to be seen. The skill is getting/keeping it 'straight' so that the light is reflected evenly resulting in a 'mirror finish'
Note the pics were taken by me (idiot with a cheap point and shoot digital camera) and haven't been through photoshop or the like
As the saying goes "the proof of the pudding" R2 your car looks like a weekend use car and it is a finish to be proud of and that is all that matters if your doing in excess of 12k a year IMHO you have it cracked Keep up the good work!
Its about you mate if you enjoy it do it and the results cant be argued with!