A few notes (I used to professionally detail cars for nearly 5 years):
Never use a brush on your paint. This will result in swirls as described above. The same goes for any kind of automated car wash. I still don't even know if I trust the "touch-less" ones.
Always use clean water, fresh soap, clean mitt, rinse and keep the vehicle wet, don't let the soap dry, gently "scrub" the paint with the mitt, try to spray off as much gunk/debris with the hose before washing, gently dry with towel, chamois etc... (don't air-dry, or use a plastic blade), use a towel for the door jams, and presto, you have a clean car.
Avoid over washing and waxing your vehicle. I have found that average dirt (always remove bird-poo, sap, bugs, etc.. right away) can sit on paint for a while and it can be easily restored. On the other hand, if you are constantly washing/waxing your vehicle, you risk scratching it more often and further deteriorating its condition than if you had just maintained it less regularly. It's better to not wash/wax if you can't do it properly. Don't settle for a quick and easy cleaning, it is worse in the long-run. Also, each time you wax your car you are taking micro-layers of paint off to even out the surface.
Clay as needed, definitely not every time if you wax often. Do not "Buff" on your paint unless it is a last resort. Most scratches or swirls may be removed with hand wax. Buff swirls are harder to remove, and are easy to get if you don't know what you are doing. Plus, you risk removing more paint with a buffer.
I used to wash/wax my cars every single weekend. Now that I don't have the space, I wash my car about 4 or 5 times a year, and wax it once or twice a year. It always comes back to its original luster, and I believe it is in better condition than if were to wash/wax weekly as I did before.
When I do wax, I use a general polish wax (can't really go wrong so long as it has a light cut), and then I use 3M ultra high gloss paste wax to finish it off (incredible shine and makes the water bead great!)
I'd be happy to answer any other questions if necessary.
I nearly forgot the whole reason for responding to this thread... I never let the dealership or anyone else wash my car. The dealer nearly always uses a brush for service washes. Just tell them not to wash it.
With that said, when I took delivery of my new Escape a couple weeks ago, I told the sales man not to let anyone wash it while I was in finance. So, he took a towel and dry-wiped the layer of dust off my new car... I gave him an ear-full for that one. I was definitely not happy, but I know that those light swirls come out with a single coat of hand wax. Not worth stressing over.
These are also reasons that I prefer to special order a new car, because there is truth to the words "Lot-Rot." Once a week in the summer we would go hose down all of the new cars and just wipe them down. I think I cried a little each time we did this.