Thinking about buying a 4Runner and will soon be posting a thread full of dumb questions for people to answer, so I'll try and give something back first...
Keeping a car swirl free is definitely difficult. You can polish the swirls out with a buffer, but they will keep coming back if you don't work hard at not reintroducing them. On dark cars your washing technique is absolutely key to maintaining a swirl free car. Here are some tips...
- Wash using a chenille pad and use the two bucket method: Sponges are junk and just grind the dirt into your paint. Chenille will allow the dirt to be lifted up into the fibers of the chenille and not scratch the paint as you wash. Use one bucket of water to rinse the chenille pad, and then dip it in the other for soap. You should be rinse/resoaping the pad every time it gets dirty which could be twice a panel or more if the truck is really dirty.
-Wash from top to bottom: Avoid wiping down rocker panels and other dirty spots before doing the upper doors or hood or anything.
- Microfiber towels: Microfiber is better than cotton for keeping swirls out of your truck. I had a lot of swirl issues until I switched. I use waffle weave MF towels to dry my cars, and smaller MF towels for buffing wax, etc.
Zaino: I have never been a fan of zaino because I believe that some of their products are intentionally mislabeled. They label glaze (which hides swirls) as polish (which removes swirls). Many people swear by them but there are products that are just as good if not much better.
High speed buffer: High speed buffers do not introduce swirls, they remove them. They can introduce some marring if you use a wool pad and if you are being to aggressive with them. In general, high speed buffers are better used by people with a lot of detailing experience because ONE SECOND of inattention can lead to you burning right through your paint (I've done it). Random orbital buffers such as the Porter Cable 7424 are completely safe and are incapable of burning your paint, but polishing using these can take forever.
ScratchX - ScratchX is a good hand polish, but I would hate to polish an entire car by hand. I would go so far as to say that polishing all the swirls out of a car by hand is pretty much impossible. You need a buffer to make it easier. Great polish, but I would definitely go with a buffer and something like Menzerna FP/Powergloss/etc (depending on the paint condition).
For my cars here is my routine...
Maxima - Menzerna Final Polish on rotary buffer topped by Pinnacle Souveran in the summer and Klasse AIO/SG in the winter
Grand Cherokee (owned for less than 6 months, getting sold to buy a t4r) - Menzerna FP with Klasse AIO/SG all year. Klasse is VERY durable and does not need to be reapplied that often.
I saw above someone mention that you have to glaze. That's not exactly true. Many many detailers use glaze to help hide imperfections but I prefer to polish them out completely. Glaze will wear off after a short time. This is why almost anywhere you bring your car to have it professionally detailed will *appear* to have taken the swirls out, but they will reappear after a month or so.
Keeping a DD swirl free is definitely a lot of work but the key, beyond anything else, is NOT REINTRODUCING THE SWIRLS. Constantly polishing the car is not an option, so what you want to do is avoid putting swirls in the paint in the first place. Chenille, two bucket technique, MF towels, NEVER bring it to a car wash (except touchless or spray car washes and never use the brush), try to keep it from getting too dirty, etc.
If people are interested here are a few of my favorite links...
http://www.autopia.org - Detailing board
http://www.pakshak.com - Excellent MF towels, autopia members get a discount
http://www.properautocare.com - Sells all kinds of detailing products.