mine is the 2014 model, it is all automatic, the front passenger airbag is controlled by the weight sensor on the seat, if no body sitting on it or NOT enough weight (a child of UNDER a certain weight) on the seat, the passenger front airbag is Disable Automatically and there is a Warning light (right at the Center of the dash) telling you that airbag OFF. If i ever need to put stuffs on the front passenger seat, I always engage the passenger seat belt FIRST (telling the sensor that no one is on the passenger seat) BEFORE i put anything there. But it is NOT advised to do so because when the car having a sudden stop at any reason or car being hit, all stuffs would shoot around like a bullet and it could be fatal. I believe it is also not legal to have kids who need to be sit on booster or baby seat, to be placed on the front passenger seat for their safety even before there was such thing as airbag. Now that with the airbag, it would even hurt them more instead of protecting them. Depending on country, state or province, i guess some of them would let you strapped down the baby carrier onto the front passenger seat (***Don't quote me for that) with the seat belt but the baby carrier needed to be facing backward, and since the baby(even with the carrier) is not heavy enough to trigger the sensor, it would tell you : passenger airbag OFF to prevent the baby being injure more by the airbag when deployed. I don't have any idea of earlier model of the iQ, so, no comment, just sharing my year model's spec. I believe different year, different model and different brand of car would have different set up and function. But I would 100% supporting to put our little love ones at the back seat if possible, they are so fragile and deserved all kind of protection and love. One phone call or visit to Toyota should be able to help with that question i guess.
