How to get top shiny again

If you're talking about the whole 'horizontal' painted portion, it usually will look allot worse as it takes a more direct beating from the sun. There are all kind of paint restoration processes. Some are even on miata.net. You could also go to any wax / polish mfr. site to get complete instructions. Basically it involves removing oxidized paint, putting nutrients / oils back into the dried out paint and putting a protective wax coating over top to help retain the oils in the paint, keeping the color rich. It's a big job if the paint is pretty bad, luckily you're working on a very little car!

Good luck, Chris