beading on windscreen/window glass.

[pachanga231]

i want to get the beading effect so when it rains or i wash the car the water just rolls of the glass. also if on the motorway the water can just roll off
i regularly clean the windows with normal household mr muscle etc internally/externally but it doesnt bead.

i read somewhere to try white vinegar which would help prevent mist buidling up on the inside, this didnt work either and it stinks 2 days after!!!