If you know anything about detailing cars, black is probably the most difficult color to keep looking nice. it's been known to show swirls, fine scratches and imperfections easily, plus, it collects dust faster than you can say the above sentences.
Until recently, I've been using Meguiars Gold Class paste to wax my Black Celica GTS. it's great at filling in swirls and fine scratches, and gives the car a show car shine, unfortunately, It is a softer microcrystaline wax that doesn't protect as well as some other waxes, so, you will have to wax more often with it, as it is prone to come off after some heavy rains & car washes.
Now, the other day, I decided to give Meguiars latest wax a try, it's called "Meguiar's Tech Wax", it comes in an odd-looking purple/green bottle, and it's a liquid wax. So Far, I've waxed my car with it once. The results? Well, I have to say, I'm totally impressed by this stuff. It costs more than gold class, and the results are as good, if not better than gold class. While it doesn't seen to do as good a job at filling in fine scratches as gold-class wax (Maybe they should make a paste version of tech wax as well), it did, as the product claims, make my car look like it got a new paint job. While I could notice a couple fine scratches still visible under bright sunlight, I'd say, as far as appearance goes, both products are almost identical when it comes to the visual results.
Something about tech wax, however, just makes the color seem deeper, the shine is every bit as good as gold class, and, since it's formulated for imports, and has some nifty synthetic formula, the protection is waaay beter than that of gold class. upon comparing the two, the results are similar, but with the tech wax, the protection lasts a lot longer, imho. And for a synthetic wax, it comes off so smooth! it has no powdery residue (gold class has plenty) is easy to take off the haze, and it leaves almost NO residue to detail out (The seams of the end-caps on my TRD
wing are usually caked with residue after waxing... now, almost nothing! I was in disbelief!) When I tried the Prestone Synthetic wax on another car, that stuff was like trying to remove dried plaster or glue! Tech wax doesn't suffer from the same problem at all.
If your car's finish is oxidized a bit, you can use a cleaner wax first to clean the paint surface, remove oxidization, and help hide those swirl marks and scratches, use a non-abrasive cleaner wax on the celica, btw.
I also reccommend that you use Meguiars No. 7 show car glaze prior to waxing your car for best results. Show car glaze is paint-shop safe (which means you can paint the car after using it!). You can apply it multiple times prior to waxing, it cleans the paint surface, and also conditions the paint to help it look glossy, and makes the color pop.
Lastly, buy a California car duster! When you show the car, you will notice that dust likes to cling to the freshly waxed surface. a couple light strokes with a car duster will take off the dust, and leave the car looking shiny and freshly waxed. I use my car duster twice daily, as there is a lot of tree pollen and crap that likes to accumulate on the bodywork over the course of the day. When it rains, all that dust, pollen, etc will collect in puddles, and create splotches all over the car, it will then need to be washed and waxed again, or I'll need to bust out the detailing spray and spend an hour cleaning up the car. If you dust it before it rains, a quick water rinse and dry and it looks good as new.
Hope this helps you...