After a Pre-wash and before a main wash (otherwise called a "two bucket wash" or "contact wash"), you want to address any specific issues with a targeted solution.

The main issues here are bugs and tar, and while we have all in one solutions that do both together, targeted products work a lot better here.  Bugs and tar are quite different, bugs are protein, while tar is quite different, it makes sense then that a different chemical will be more effective for each.

It might seem more work to have a dedicated bug remover, and a dedicated tar remover, but it is much more efficient as the products will get the job done a lot faster and easier.  Spray Fireball tar remover for example and you instantly start to see tar start to run.  It won't be effective on bugs; it's not meant to.  For bugs Fireballs Bug Remover specifically targets the protein of bugs, expanding and softening it so that it can be safely and more easily removed.  But it won't be effective on tar, it's not meant to.  ValetPRO's Glue remover is very good for removing glue residue.  Fireballs pH3 is a bit different, its an acidic car wash designed to remove light water spots and lime.  Most car wash soaps are wither pH neutral or Alkaline, but an acidic wash like pH3 is useful for removing alkaline minerals which in NZ is normally lime watersports or dust.  Pollen on the other hand is acidic, and while a pH neutral option will work, for stubborn pollen an Alkaline prewash will make the job easier, just don't go too heavy or it may strip waxes or sealants.  

If you are applying a ceramic coating after a proper wash and clay wiping the surface with reborn is critical to ensure a proper bond.  We often make kits with coatings reborn and good cloths at cheaper prices than buying them individually to ensure people do get the reborn as it does make a difference.