Suggestions for one step.

[Tonyace_121]

If it's not too bad try the Meguiar's D-151.
Often it works very well for me, but the finish is really bad the results or so so.

Meguiar's White Wax is another good one, over the counter too.
But from reding your post I'd go with the Meguiar's UC then top it with a good sealant.

Thanks for the tips..