One thought in maintaining (and bring back to life) your paint finish is to try
Clay Magic or similar clay-bar products. They work wonders as a pre-wax step in
removing impurities, water spots and environmental damage.
A few other notes: work in shade or inside your garage (with the door open, to
let the dust and vapors escape).
Once the car is washd and dried, going over the whole body with the clay bar
(follow the directions.. it comes with a bottle of spray solution that must be
liberally applied before using the bar), then see how the paint looks. You will
notice an improvement in how it feels (like glass if you have decent paint).
I hesitate to recommend a machine polisher to anyone without experience. it's
too easy to use just a little too much force or linger for too long on the many
raised edges and ridges in our bodywork, and you can polish the paint right off
without much effort.
I have been happy using a series of Meguiar's products: their fine-cut cleaner
(#2, but be careful with this, as it's more abrasive than it sounds) followed
by swirl remover (#9, and usually a good starting point in the wax process
after the clay bar), and then their high-tech yellow wax (#26). One key to
getting a good show-car shine is to let the final was sit for a day or two and
then wash the car. The final buff of your dry car (I use cotton diapers I buy
from a diaper service) usually brings up a clear, even shine.
I do not find that any of these products provides a long-lasting shine if the
car is exposed to the outdoors or frequent washings (I must confess that I
don't have to wash my Imperial or NYB more than once a year, thanks to SoCal
weather, keeping them covered, and their not being driven regularly). On my
daily drivers, especially my black cars, I find Zymol to provide a
longer-lasting finish. It also goes on and comes off easier, though the
follow-up wash and dry a day later is still a necessary step to even out the
finish.
Hope this helps!
Chris in LA
67 Crown
78 NYB Salon