@InfiniteQuestion
It's positive to see more people researching this area of GTA V modding.
Here is a some additional information.
You guys have to remember how interconnected/interdependent everything is.
To REALLY control ambient vehicle densities, both parked and driving, requires comprehensive configuration of both gameconfig.xml, zonebind.ymt, scenarios.meta, settings.xml(Documents), popcycle.dat, vehicles.meta, pedpersonality.ymt and popgroups.ymt.
And even ALL the individual path .ynds, plus ALL the individual Navmesh .ynvs. if you want to adjust all this on a "per street/neighbourhood" level.
Beginning with changing values in the gameconfig is a really good start though, and I wish you nothing but good luck going forward.
Have a nice day and happy modding.
Modifiver.