Re: Random Orbital Buffer
Unless you try really hard, you won't introduce any marring.
These buffers are basically liquid wax applicators, and for that they're just fine. If you opt for paste, just use a spatula or plastic putty knife to apply product to the buffing pad.
Some of these buffers were up to 10-3/4" in size -- so you've got a much larger area to which you can apply wax with than by hand. But keep in mind that you'll need to apply by hand where the large buffer surface can't reach.
Inspect your buffer and imagine guiding it across the surface of your new Camry and establish whether or not you want to invest in some bonnets. You can certainly use the terry bonnets that it probably came with, or even get the foam or microfiber depending on what's available for that size -- for a one-step product, either one will do just fine.
Whether or not to use it is really up to you.