I have watermark on my car too, a lot... i mean really really a lot and kao kao..

i am your typical local consumer, just wash car and then wax it with the brand 'kit'.

1.My initial exp was like this, i bought a can (round one) soft 99 from jusco to wax the car and the watermark disappear and i thought it was good, and after a few car weeks later it appeared. I thought it was gone, but in fact it was hidden.
Then i run out of it
2.I couldn't find soft 99, so i switched to "kit" as that was the only brand i can find in the whole retail in stores in penang (jusco, tesco, cold storage, gama). I use it and realise it takes at least 4 times the effort(more force and time) to make the water stains disappear( i use hand, no kaching buy machine)

Q1.My question is how do i make them disappear completely or at least hide them more easily?

I am currently in Taiping for 2 days and just now i went to tesco and i found this blue colour soft 99 (did not say remove water stains) and also this meta clean soft 99 can (it says remove water stains).
Q2.Will this really remove water stains completely or will it work like my previous soft99 and just hide it?
Q3.Should i get the blue colour normal one since my car is just white colour and not metallic, since i assume the meta clean 99 is for metallic paint or should i get the meta-clean one since it says on the back (remove water stains.)
Q4. I also read something on using vinegars, does this work?
Q5. I've also read about claying, does this remove water stains, i've read some forum they said it does with some soap water while others said its used to remove stains and small dirt to prep the car for polish. So how does this work and where do i get them?How much are they?

I get irritated i see water stain after car wash, i also have some bubbles and rust on the roof, but i want to at least clean the stain so it don't look ugly. Any cheapo alternative, don't ask me buy the exp exp stuff like megs, im kiamsiap. Thanks in advance for people sharing on this

any reccomendation, they sell clay? or cleaner?