Hi, we have a transit like van (a vauxhall vivaro long wheelbase) that we've partially converted (i.e. insulated and added a bed to), but we don't have proper ventilation. Prior to lo arriving we would just leave the windows down a bit. We'd like to camp with lo in it now they are over 6 months but worried that the lack of air flow might put them in danger. Does anyone have any experience of camping like this or any arguments for or against it? Thanks in advance.