Without wishing to start a long drawn-out debate on the MoT standards etc...
But how does this 'Heath Robinson' setup sit with the MoT requirements??
Yes it has Springs, yes they 'suspend' the car - but given the manual control and the possibility of getting uneven pressures in each airbag and/or uneven ride heights from corner to corner, thus causing an unstable platform....does this contravene the current MoT Standards???