I have another product, which do I apply first

Since our Liquid Wax lasts so long, this should always be the very first product applied to your vehicle. The only exception would be if you were using a ceramic coating, then it would be, ceramic coating > Liquid Wax. After Liquid Wax, we highly recommend using our Hybrid Wax. We've had unmatched results in terms of longevity and shine when using our Hybrid Wax on top of our Liquid Wax. There would be no need for any other products besides these two.