i fixed the glass with perspex till i get a new one,
baring in mind how easy it was for the theif to just smash the quater glass on the passenger side and grab the disc i've fitted a tamper proof tax holder to my other car and will do when i get the duplicate for this one
also moving them to the top of the windscreen rather than the usual bottom left corner
also went over the faded number plate and model on the tax disc before sealing it , as the summer sun had faded the hand written parts, another gem for the theives,
the theif never even opened the door or looked in the glove box, just purely for the easy to grab disc
i'm hoping that the tamperproof holder which laminates the disc in the plastic and the obvious warning around it deters them from my car next time
they are only old skodas with no alarms etc, but i cant see it putting them off if the want your disc
i got my taperproof discs from halfords, had i of seen a post like this else where before the even i would have already got the stuff and been aware
so i hope this message is of some value to others here
i never worried about theif from my cars because the are old skodas, but with todays clamp downs on tax dodgers this sort of thing is getting more common
Creeps up behind Laura with a bucket of 20 litres of Custard and tips it all down Laura's head and neck an sticks bucket on her head 
