I am working now on a script that will help with car parks. It is supposed to create randomise cars over even huge car parks. with one click solution you can generate cars parking spots and set colour scheme, probability and even angle of cars. you have control on number of spots in length and width, size of a parking spot and angle of parking spots.
quick overview: select cars - add selected cars models to library(models have to have preffix: "pix_"
create parking - create parking plane on ground geometry
car pro - car probability (% of cars on parking spots)