well my son is 14 monthes old
i drive my 1/18 in the living room while he's watching and kicking with his legs (i think its happiness) and when i wrench on my car or engines, i make sure he's sitting in his food seat/table and watch what i do, it may sound crazy but when i wrench, i explain to him what am doing exactly with all the tips and tricks and he listens
when he starts to yell or cry, a nice 1/8 onroad foam tire will calm him down as he loves licking the foam
just make sure it a new tire not to poisin the kid
cheers
Ali