Has anyone used a seat belt extender like this with their booster seat? If you have any safety information please share. We are expecting baby number 2 next week and we have installed the infant seat base in the center and have our 4 year olds booster seat on the side. It is really hard to reach the seat belt buckle for the booster seat because the infant base is in the way. I saw this extender and wanted to give it a try but wanted to see if anyone else had experience with it first?