Back in June 2016 ( 3 months back), I corrected and sealed my wife's daily drive using a full suite of Meguiar's products from Ultimate Compound, Ultimate Polish to Ultimate Paste Wax. You can read about it here.
As I was washing my wife's daily drive this morning, the sun rose earlier, seemingly wanting to reveal something to me :-). Great revelation - a lot of water marks and stains on the car. It was quite bad considering that the car was waxed less than 3 months ago.
I am not sure why the wax is not doing its job as it is one of the most hyped about waxes/ sealants in the detailing world and it is not cheap.
Comparing to my own daily drive that was sealed almost 5 months ago, the condition on my wife's daily drive is far worse. My daily drive was sealed using Autoglym Extra Gloss Protection. There are some watermarks and stains on my car but not as bad.
However, this observation; although with evidence; is still inconclusive. The two different cars could be exposed to different environments. So to be fair, I have planned to tape-up my wife's car into sections and test with the following products and conduct a long term observation test. I actually do not prefer taping up a car because of the adhesive residue and unprotected surfaces under the tape. I guess I will device a slightly better method that does not leave any surface unprotected. I already have an idea... stay tuned. Happy detailing.
From USA: Meguair's Ultimate Paste Wax & Finish Kare 1000P Hi-Temp Paste Wax (FK1000P)
From GB: Autoglym Extra Gloss Protection
From Japan: Soft99 Fuso Coat