you can't buy "Finest" by yourself - it is licensed only to detailer tha they train. You can use Gtechnic, 22PLE, Opti Coat 2.0 and other perm coatings that work well. I use them when I know a car will not be washed often and taken care of. They are permenennt coatings and will have to be polished off.
Remember: the key to great long lasting gloss is in the polish stage and needs to be done with an orbital.....the hand cannot get mirror results as it does not move at 1500 rpm. Use any last step you want after polish for great results....
I take care of my stuff and like detailing so I only use polymers that "coat" but allow reapplication. My favorite is Blackfire Crystal seal - no buffing, it wipes on and you are done.... and looks like this for 3 -4 months:
