Reasoning:
Original Riddle: Ipsumstan - Ipusm = motor/engine in Latin, "-stan" = "the land of" (i.e. Pakistan.)
1st hint: A son to a mother and 5 other siblings - The mother is Driving Park, and the 5 other siblings are Test Course, Motorsports Land, Beginner Course, Gymkhana, and Complex String.
2nd hint: Its predecessor is Ipsumloremstan = Again, Ipsum = Motor, "-stan" = the land of, but lorem = sport. The predecessor is Motorsports Land.
3rd hint: The mother is "Car's Playground" = Driving Park.