Meguiar's NXT 2.0 doesn't suck. Don't listen anymore to the person that told you. It is one of the easier/easiest products to use and hides lightest scratches easily, but it's downfall is at least, in three cars I used it in, it doesn't last very long. Meguair's Ultimate Wax is also just a few dollars more and is better overall. So there's no need good reason to buy NXT 2.0 when Ultimate Wax is right next to it.
However, I do enjoy and miss how easy it was to use and how very little you need. .5 oz to 1 oz depending on your car.
Any synthetic wax that requires time to cross-link is a sealant. For your situation with cars parked in the sun, I get 1 year protection using Armor's All Extreme Shield Wax. However, that Wax is so easy to apply. You just wet your paint with it and wipe with the other hand holding a small microfiber cloth. After a panel or two your cloth will be soaked enough that you use it to apply/wipe. You can apply it to your car for 15mins after every wash if you like, but there's no need. I have used it nearly 3 years across 4 cars in different settings (2 parked outside, 1 garaged nightly, 1 garaged nightly + parked inside a structure)and it's averaging 11 months... pretty much 1 year.
I suppose if you wanted a yearly detail regimine:
1) clay-bar
2) Meguair's #7 glaze (re-condition your sun dry paint, leave light scratches alone)
or
Mother's California Gold Pure Polish – Step 1 paint cleaner (clean paint, scuff off edges of lightest scratches)
3) Armor-All Extreme Shield Wax or Meguair's Ultimate Wax (just to complete the Meguairs line of products
)
4) relax with alcohol.
Anytime you wash, use wax-as-u-dry.
