Most leather in cars these days is 'coated' leather. This is essentially a 'painted' leather with a clear coat finish over the top. The leather may or may not be dyed through with aniline dyes prior to the finish coating. The simple test as stated above will tell you what type of leather you have.
Essentially it is this top coating that needs looking after. Cleaning is vitally important as the top coat will wear away if allowed to become dirty. Dirt on the surface will aslo become ground into the finish by constant abrassion.
'Conditioners', balms, feeds etc (traditionally oil and wax based) cannot penetrate this finish as you rightly say so are not worth applying - they can also leave behind residues on the finish which will only attract more dirt if allowed to remain.
A protector will make the finish easier to clean and also inhibit dye transfer etc on pale coloured leathers.
Leather however finished has to remain breathable and it will allow the movement of moisture back and forth (transpiration) so the use of water based cleaners and protectors will keep the leather correctly hydrated which is essentail to keeping it in good condition.
The routine for correct care should be
Protect from new
Maintain with a regular clean or maintenance product
Deep clean with a foam cleaner once or twice a year
This will prolong the life of the finish on the leather
Hope this helps
