The channel is called "Awning Rail", "Awning Channel", or "Awning Track", depending who you buy from. The strip is called "Awning Rope" http://www.sailrite.com/Awning-Rope-Vinyl-3-8 this is just a sample, as I don't know what the correct size is. Both are available at Sailrite
It fits the track on my 2011 MPG. If my research is correct, some MPGs might have different diameter Keder Rail installed. Please note that you will need to find somebody with an industrial type sewing machine to attach the stuff to fabric. A local leather shop did mine.