On the new ones the sound inside is a different story..
See that small tube coming off the intake pipe? That has a resonator ("speaker") in it and it's piped thru the firewall next to the brake pedal.
It creates a low growling engine sound that to the driver, seems to be coming thru the firewall. There's a little piece of foam in the mouth of the pipe that if you take it out, it changes the sound to a more hollow intake sound due to the resonance of the flex tube.
To the OP's question ... As far as the sound inside the car goes the answer is simple.. Ford cheated.