Hatchbacks are almost cheater rides, 1-2 subs work best fired up.Bounce off back glass and goes straight for the dash.
Over the years I've had a lot of systems in pickups, the 1 thing that always got me is I've sold systems to others with hatchbacks and it's not nothing for a hatchback car to pick up 1,2,and even 3 decibels over a truck cab.