My last coat of Meguiars NXT has been on my car for 3.5 months, with about 6500 miles, driven through plenty of rain storms, and about 12-15 car washes, both home and commercial touchless jobs. It still beads nicely when wet.

 

Odd, I've used Gold Class wax on mine and my car always beads nicely. I don't wax it all that much, but I certainly keep my car fairly clean. It between waxes, I use gobs of Quik Detailer and I've never had a problem with Meguiar's. I don't know why you haven't had results, but I love Megs in the every day rain of Florida.

 

I used to use Gold Class. It was easy to apply and remove, but it never beaded water after 3 weeks in the sun and rain of NJ. I never had to do a lot of prepwork with Klasse AIO and it has managed to bead water after 9 months of mixed weather in MI (rain, snow, salt, sun, etc...)