There is a bit of “cargo space” behind the seats n the 152, sometime they put some unlucky guy to crouch in there as well, just don’t tell the the FAA 
(google “cessna 152 back seat”)
So I usually modify my flight model cfg like this
max_number_of_stations = 3 ; Number of payload stations
station_load.0 = 170, -7.5, -0.86, 0, TT:MENU.PAYLOAD.PILOT, 1
station_load.1 = 170, -7.5, 0.86, 0, TT:MENU.PAYLOAD.FRONT_PAX, 2
station_load.2 = 0, -9, 0, 0, TT:MENU.PAYLOAD.CARGO_CABIN, 3
I do FSEconomy flights where you can take 1 pilot 2 passengers or some cargo, this way I can set my payload to match it. Also I think this is realistic
DRF30q if you agree you might want to adopt this?