You can't make it really flat with hands

Hmm, that stain that comes from your car porch ceiling is some form of cement residue if not mistaken. U should handle with care because trying to scrub it off too hard may induce scratches, even on glass. For your glass, using a razor blade and gently scraping may be able to remove most of it.
Hmm, piano finish is quite tough to restore. Mine also has scratches but I did nothing other than regular damp wiping because I worry if I attempt to polish, the remaining haze will be quite difficult to finish. The main issue is unlike car paint which I know is made of clearcoat topping, I dont know what is made of the piano finish for interiors.

Perhaps other sifus here can share a more meaningful experience in dealing with this.

https://www.youtube.com/watch?v=4an83rCMPK0
https://www.youtube.com/watch?v=G0vCMo7EyFY

This is my reference point for not doing my interior piano finish. Hope it helps.

U could try compounding by machine and polishing/finishing by hand, that could work.

You dont need ipa wipe down after this . your ipa induce more scratch

I already stop using 0**** product when i found their product is so hard to understand and misleading 
Any "Body shop safe" finishing polish e.g sf4000 m205 3d one  work , because we already know it has no filler , so u dont need to ipa wipe down
Yes , it more "soft" than Soft clear coat
Your best bet is polish with a "body shop safe / silicone free" finishing polish and a finishing pad with low speed and seal it with PPF .

Lol, now u understand why I am hesitant to polish piano finish stuff.

Just something that came across my mind. Many years ago when I was a kid, I used to play Tamiya toy cars, and there was a black car body that I polished to a fairly high gloss finish. However, instead of using a car polish that was meant to work on clearcoats, I used plastic polish (I think it was Autosol).

So apart from M205 on Meguiars range, u could try the likes of PlastX. Do go gently though.

PPF no, but I can suggest a cheaper alternative since u arent doing it on the car itself. U could consider clear sticker wraps that kids use to wrap their textbook covers once upon in time. Its available in stationary shops and should be quite affordable.

can you suggest a product to 'compound' ?

Not really new tricks but 😁

I was already curious about the relevance of pouring car wash soap into a pump dispenser, as it takes alot of pumps to have the right amount when making wash bucket soap. Now that u mention foam lance, then it makes perfect sense, hehehe

Though, I could suggest a more cost effective pump would be using recycled body wash bottles. Just my 2 sen anyways

If budget not issue, Rupes. If budget is issue, Osren, ShineMate.

I personally using Rupes LHR21Mk2 and Nano iBrid, not yet ROI after 3-4 years owning them cuz rarely use (maybe 1-2 times a year only). Abit regret buying, lol.

LOL im sorry , i mean karcher hd6
Yes , you dont want to use this as your daily wash
Use this only if you want to apply any protection later.

rm1k diff i think ,
if you love foam , hd6 totally worth it!
well , maybe that just me
i got many friend bought k2/k5 ,
after they saw the different
they end up buying hd6

Hi guys, I am first time owning a car, a silver hatchback.

Been a month plus since the first day of getting the keys, and it was getting dirty, so I decided to wash myself.

Did some Googling and found that Meguiars seems to be good, so I bought the Meguiars Gold Class Shampoo, the Meguiars Washing Mitt, and for drying the car, I didn't had enough money in my wallet that time so I didn't buy the Meguiars Magnet Drying Towel which I thought was quite expensive for a towel (it was RM97), so I bought the Supreme Shine Microfibre Towel instead because I thought this towel can dry the car too although the box says that it is for drying off wax and polish.

So my first attempt, I filled up two buckets, 1st bucket for the shampoo, and 2nd bucket for the clean water.

I started by wetting the car with a hose (the hose in my garden, just a normal hose like those you use for bathing, the yellow one).

Then, unfortunately I think I was dreaming, I forgotten to use the 2nd bucket for rinsing, I just dunk the washing mitt into the 1st bucket, spread the shampoo on the car, dunk it again into the 1st bucket, continue spreading the car with shampoo, and after covering the whole car with shampoo, I rinsed if off with the hose in my garden.

I dried off the car with the Meguiars Supreme Shine Microfibre Towel but it was so hard to dry. The towel got wet quite fast and when it was wet, it couldn't dry the water.

When done, the car seemed to look clean, but the washing mitt was slightly black with dirt, and the Meguiars supreme shine had black spots too.

I think I made lots of mistakes.

Should I get a new washing mitt and microfibre towel? Or can I just wash it? How do I wash it?

My mitt is already greyish after only one time using. Can it come off? What do you use to wash it?