Have used 303 Fabric Guard for years now, like the results a lot but reading on other products I could get even better results. If I wanna shell out more $$$. I had come down between CP Fabric & Gtecniq I1, then I saw that I1 comes in a 5 liter jug if you buy directly from their site. I believe there is a Gtechniq rep on here. I`m curious what the shelf life of an open container is? I definitely don`t need 5 liters, but it would be like half the price. That makes it hard hard hard hard for me to resist. I just can`t find anything about how long it`s good for once opened. 5 liters would probably last me a long time.