I'm hoping that the 'forward draft' holds it in place against the head restraints, but you're right that too much turbulence might make it flutter. Then again, the perspex stopper sold through Miscellany was in the same location but held by elasticated straps, so I'm hoping that mine will sit there 'steady as a rock'. I could use an elasticated add-on if necessary for motorway trips - because when I bought my camping mats (garage door insulation) from Blacks, they each came with two black elastic fasteners which are exactly the right size. I just need to find where I stored them in the garage.
