Thanks all for very useful comments and to moderators for re-opening thread on my request. First reply I got after 5 days and meanwhile I went to the renowned shop for both body and windows job. Windows as i mentioned were clear after cerium oxide treatment but i worked for front side windows only as it was taking a lot of time to clean with cerium. Around 60 minutes on one side window. First wet the glass, apply cerium with hand, start buffing with drill and pad, keep the glass wet, rub with a rubber pad, finally clean the glass. Now repeating all this three times was giving the results.
I am also aware that the hardness of side windows glass is more compared to the front wind shield and cerium may have bad effect on front shield if used.
The car i purchased last year as brand new 2014 land cruiser. I am not sure if it originates directly from Japan or some other country.
The acid rain didn?t really eat up the paint, it was like a layer sticking to the paint, and if i rub my hand, it feels like a coarse/rough surface.
The best workshop (claimed by GCC people) with the highest rates required one day. His knowledge was limited and it seemed he has some pet formulas for all cars. It took one day and on my return the paint was shining just like new and the job was impressive.
However the windows were same, he showed me some label less bottles and only hand rubbing used for windows. I gave him cerium and he was reluctant to use as he had no drills or pads.
I then decided to work the wind shield with cerium myself and it worked very well for the recovery. The HF (Hydrofluoric acid) etches the glass but depends on concentration. In this case a very thin etched layer and if you wet the glass with water, etched layer becomes non-visible. I'll post some pictures to show effectiveness of cerium on the glass.
The rear window has some water marks along with etching, i believe cerium can easily remove water marks.
Now as per pakwheelers advice, I am looking to buy a water proof cover, detailing spray, wax and increase frequency of washing.
Here in gulf, plastic covers are available for the front bumpers, bonnet etc. to reduce effect of mainly sand blasting, which is the sand affecting the car at high speed. For a long drive normally i have to put a soap solution on headlights just to avoid sand pitting.
In my company hundreds of cars are already effected by HF acid and result is blur windows. Interestingly all the cars are sent to a DIY cleaning shop and after cleaning the windows appear better but in few days all windows completely become blur, then company has to replace the windows. To my curiosity i met the cleaning guy and he was using a mixture of acids and HF itself for the cleaning. Unaware of the effect he is actually ruining all the car windows but getting financial benefit of replacing windows later on by his own company.
To avoid glass etching, some has put plastic sheet outside of the windows but due to the environment effect it looses good looks soon. For the wind shield and rear window, wipers destroy external plastic easily. Best remedy seems keep car under water proof cover and do frequent wash.