you said those little wireless radio control cars use IR. that is incorrect. they use radio, it is just on a weaker frequency range and doesn't travel far. IR is an optical technology requiring line of sight. your tv remove is IR. put your hand in front of the remote and try and turn the tv on. now turn and face the wall opposite the tv and aim at the wall and turn your tv on. the sensor can see the light bouncing off the wall. it does not penetrate.