Was having lots of trouble recently with my window regulator (glass falling out) anyway got the whole thinkg back together the other day.

The reason the glass is coming out is because when you wind it up one side of the glass doesn't move freely, gets stuck and then the window glass goes sideways and pops out of the rail. So I think i need to get some of that grey lube stuff that is in the rails/guide channel.

Anyone know what it is called and where I can get it from?

Paddy