plastic insert/runner

[Sir Brixalot]

Having tried and failed to stop water getting in sliding window I eventually tried to seal it up completely with windscreen sealant but its now hot in the back for the kids. Water still getting in anyway. I noticed that the sliding glass jut sits on bare metal and water gets under. I have bought a replacement early door for the other side and the glass in that door also sits on bare metal.
I think the moving part of the glass should run along a plastic insert. Does anyone know if I can still buy them or had anyone come up with a home made replacement? Should the plastic insert run part way up the veritcal part of the frame because when trying to fit brush seals they always bunch/ruck up on the curved part of the frame where the horizontal meets the vertical stopping the window form closing. Hope this makes sense

[jamesc76]

think posting a pic might help then people with the same type could help more!