I was thinking about something good ways because the gloss got foggy due to volcanic ash.
Before I used to try the professional coating and other DIY coating products, but almost all I was not satisfied with results, such as the cost or durability.
At that time, I found Super Pika Pika Rain Ceramic Coating which has many good reviews on the Internet, and then I tried it for the first time.
I washed my car with the original shampoo which was contained the usual car shampoo and the dish soap which I expected removing the oil.
Also the instruction says that I should try not to remain any water, so I wiped and blew the water off carefully.
I applied the solution with the attached sponge.
The solution spread very well, so a little amount is enough for a whole car.
(Not to put on the solution too much!)
I think that tips of application were repeating the works (applying for every small areas, wiping the solution and checking results).
The photos show after application. It has nice results as many reviews.
There were a few rainy days, but I could check the dirt decrease before application.
From now on, I hope that this effect will keep for 3 years.