Don't know if this has been found before...
If you have a new Sprinter with the Factory E track here is a source for the tie downs that snap in this style of track.
Ancra products are available at most trailer jobbers.Kinedyne makes the smaller ring but having both, I vastly prefer the HD double stud type, no rattles when you arent using them so you can leave them in the rails.
6 of each and I was only 50 bucks.
http://www.ancra-llc.com/truck/pdfs/specialty.pdf
If you have a new Sprinter with the Factory E track here is a source for the tie downs that snap in this style of track.
Ancra products are available at most trailer jobbers.Kinedyne makes the smaller ring but having both, I vastly prefer the HD double stud type, no rattles when you arent using them so you can leave them in the rails.
6 of each and I was only 50 bucks.
http://www.ancra-llc.com/truck/pdfs/specialty.pdf