Not sure if it's the same in NSW but I recently purchased a car with 3 rows and was told by the dealer that it's illegal and unsafe to put a capsual/baby seat in the 3rd row?

Was a bit suprised considering we purchased the car to fit our (soon to be) 2 plus my 2 DSS. We are planning a 3rd down the track, and since children need to be in car seats until the age of 7 it will be squashy in the 2nd row.