Review on Febreze Car Air Freshener Vent Clip, Gain Original Scent - 8 Count - Odor Eliminator by Joshua Morales

I don't know if it's just my cars or what. I have had 4 different cars and have used these things for years. They all claim the scent lasts 30 days but mine wears out after about 10 days. No matter what car, no matter what "setting" I set it to or how much air I push out of my car nozzles. I bought them because it was cheaper to buy them here than the previous place I bought them. Am I doing something wrong with them? I keep buying them because those 10 days are actually longer than anything I've ever tried (and forget all those dangling things hanging from the rearview mirror). They smell 5/5. Beautiful and fresh, like fresh linen. However, since they don't even last half the stated time, I give them -2 stars. They fit snugly in the air vents and are thin enough not to be overwhelming.