FWIW, Zaino is availible in CA via Mike Adams at
Car-Fanatic .
The Dawn people refer to is Dawn, the dishwashing soap.
Aynway, it sounds like whatever the shop used was some kind of polymere similar to Zaino or Klasse or Blackfire. If it was a wax and they recommended to use Dawn, then it is no (carnuba) wax. Dawn with warm water works great for taking off all the old wax so I doubt they would advise you to do that if they think it will last a year. It is a little to strong for weekly washings, but good every once in a while (6-mo or so) when you want to start fresh. Dawn does not remoce polymere sealants like it does wax, but over time it will wear the protective coat away. I don't recommend using it for weekly washings.
So, what do you do? If the water still beads, try picking up a good car wash soap (
without wax in it) and some quick detailer like Meguiars Final Inspection (profesional) or the standard quick detailer. Wash and use the QD and it should maintain the look you had when you picked it up from the detailer.
If you did not care for the look the detailer did (sealants tend to have a certain look to them), then you may want to use some wax. Sometimes the oils in wax break down the sealant and end up with an inferior finish. Some combinations work, others don't and with no one knowing what product the detailer used, I'd stick to the wash and quick detailer until you notice the water not beading in the rain like you want it to. Then, you cna start fresh with a good prep and wax if you'd like.
Oh, since I suspect a sealant was used, you can use a clay bar over the top of it without removing much of the sealant's durability. However, do you think the car needs clay? Maybe the detailer did it already. Run the back of a finger across the paint. If it feels smoother than a baby's behind, you are fine. Note: there is a difference between slick and smooth. Clay bar makes it smooth. Wax and sealants make it slick.