Could you fasten his coat over the car seat strap somehow?? Not sure if/how that would work but could be worth a try.

xx

I don't drive but when my eldest was around 3 he started doing this and my mum had picked him up from nursery he houdini-ed out and mum pull the car over and told him the police would take nanna away and tell him off seems extreme but hey presto - when he next went to do it she called from the front "remember what I said about the policeman" it worked - he rarely did it again. However he was a tad older
good luck and let us know if you find a solution

my sister in law brought her daughters, who were both excellent at this. she brought them a new toy that kept hands busy, this worked till they forgot about the straps.

but to just scare you all, rich got out of his chair when he was 4 so it was a booster with the back piece just normal seatbelt.

going on holiday driving down the motorway at 70 mph and i get a tap on my shoulder and rich was standing between the 2 front seats.

i pulled over after nearly having a heartattack, i had to put him in the front in the seat with me, i was on my own and he was fine then lol

child aviation restraints

expensive thou

http://shop.babyworld.co.uk/DisplayDetail.aspx?prodid=2450