I have a Summer Infant Piddlepad for my husband's car, and this one for my Diono carseat. No matter what I do, it shifts and moves and does NOT stay in the spot it should be. Everytime I have to put my son in the car, it has to be adjusted. I thought it would work well, since the carseat is the same make. Threw it out and got a second Piddlepad.