So thanks to a friend who mentioned the car seat poncho, I looked into it and fell in love right away! However, being the frugal mom I am, my second thought was, "I can make that for a lot less."
I looked on Pinterest and Google for a tutorial, and found one: Prudentbaby.com
If you are wanting to make your own, I suggest printing the instructions (clicking the image will open it larger, then print) and watch the video posted from PrudentBaby.com
They are very easy to make. It took about 6-8 hours to make all three.