WARNING... long post about object duplication ahead

Hi, while I have asked similar questions before, I never got an answer, that would satisfy me completely.
I know about particles and hair in Blender, I know about duplifaces and dupligroups. Now they all work a little differently and for what I am trying to achieve, I’d need something from all of their features.

Duplication using hair:

  • the ability to input a a number of prototypes, that get chosen to be duplicated randomly, thus creating variation
    +can easily control the number of duplicates independently from the source object and distribute the duplicates randomly
  • I can’t directly control the transforms of individual duplicated objects

duplication using dupligroups:
+can duplicate a hierarchy/group of prototypes
+can control transforms of duplicate
-only creates one duplicate per source object

duplication using dupliverts:
+multiple duplicates per source object
-no randomness
-can’t duplicate groups/hierarchies

  • no control over transforms of individual duplicates

duplication using duplifaces:
+multiple duplicates per source object
+can control transforms of duplicate
-no randomness for amount, distribution or transforms

I would like to replicate my workflow from Modo, which has quite a robust duplication system, called Replicators. Let’s say, I want to populate a parking lot with cars, the parking lot is not your typical ‘grid type’ though, but some of the spaces are rotated to fit the non-rectangular floor-plan of the area. What I would do in Modo:

-Create a replicator, that has 2 inputs: Source and Prototype
-for the Source, I’d use an object with a rectangular polygon for every parking space
-for the prototype, I’d use a group of locators (null objects), that have a different car model parented to each of them, where the car model can be a complete hierarchy with every single part being a separate object
-now just change some settings of the replicator item:
-the source has to be polygon, this way, just like duplifaces in blender, the replica inherits the rotation of the polygon
-tick the ‘replicate child items’ boolean, to duplicate whole hierarchies
-there’s a percentage amount, which controls, how many of the polygons get populated with a replica
-a seed value to control all randomness
-random rotation, translation and scale
-with a little bit of rigging, I can add a random rotation with incremental values, lent’s say 180 degrees, so some cars are parked in reverse and add a few degrees random rotation on top of that, to make it look more organic
In Modo, you can also use vertices as a source and control the base scale, rotation and translation of the replica placed on that vertex with a vertex map.

Is there a way to get this kind of control over duplication in Blender? If not, is it possible to place a feature request?
Thanks in advance.

Did you try to comb hairs?

not really, but can you control rotation of a car along the vertical axis by hair guides? Also, if this work, I imagine this would be quite tedious and inexact, probably having to manually comb every strand of hair, opposed to just doing an array of polygons, that have the same normals and tangents.