I think that they were discontinued for a short period of time......as soon as I caught wind of it, I bought 8 from my local dealership. As soon as I 'stocked up', I also read on the forum that AC-Delco was going to continue to manufacture this 'Ultra Guard Gold' UPF-44 filter for C-5 owners. You might want to see if your local dealership has any in stock or can order some for you.
I have solicited several on-line and local vendors. This filter has been MD'd (Manufacturer Discontinued). I would really like to believe that Delco will reconsider or replace in their product line? It's their call... :-? :roll: