and the lg is basicly permanent unless you take special steps to remove it yes? so under normal conditions every aplication builds over the old one?

As any other polish or wax, it will wear off over time, especially if you run it throuh alot of non soft cloth auto car washes..generally by the time a 3-6 month period is up, its starting to wear thin, and you will notice this each time u wash the car, as it wont bead or "sheet" off as well...
willwren did a test on his old red honda..waxed half with LG and half with meguiars gold class (i think) The LG BY FAR held up WAY longer, as you could clearly see the wax line.

There are 2 other cars in my household. They both have Mothers Wax. My car has LG. After a few months, the water still beads up on my car, but does not do it anymore on the others. That'* a sure sign that the LG lasts way longer than the wax.

Long-term wax test