Mother's is a mild 3 step system. If you use one or two coats of the step 3 (wax) after you've prepped it with 1 & 2, will give you decent results. You will need to accumulate deposits of step 3, however, if you want it to last longer. I have found that Mother's is among the shortest lasting of waxes available otc if used sparingly.
The depth of Mothers is very good once you have an adequate cover on your prepped car (I have had to put several coats on in the past, but I'd say no more than one or two during one session), and I'd say that you wouldn't need more than 4 coats for three or up to six months in good weather.
Try out other carnauba products when you have an opportunity, as you may be surprised in how much depth you can achieve with the right prep process and quality products.