OT/ Auto Wax

[ggehrke at gmail.com (GGehrke)]

Clay bar is meant for impurities in the paint - such as tree sap and
industrial grime that settle on the car and embed themselves into the
paint more permanently than washing will usually take care of - not so
much for water spots.  It is (contrary to popular belief) slighly
abrasive just by nature, so it will help to "smooth out" the clearcoat
(which is what you need if you've got oxidation from water spots) but
it's not really the right tool for the job.

What you need is a rubbing compound (if they're really bad and/or to
take out scratches) or a cleaner wax if they're not too bad, as Cathy
mentioned.  I say starting with a clay bar wouldn't be a bad idea,
because that gets out the grit so that when you polish it, it doesn't
free itself and scratch up the paint as you rub, but I would follow it
with polish.  If it's a car that you want to really detail up nicely,
I can direct you to more resources on detailing.  Until I got my VW, I
was driving a much more expensive car that I couldn't really modify,
so all I did was pamper it, and I ended up learning a lot about
detailing. At least once a year I would spend a weekend to strip all
the wax and such off it, claybar it, polish and pile up about 7 coats
of Zaino.

-Grant-