Eddie Bauer car seat and cover?

Rachel • This is the result of having sex.

I have this:

http://www.target.com/p/eddie-bauer-sure-fit-ii-infant-car-seat/-/A-17289420

And was wondering what cover to buy for it? I bought a pretty generic one and it would not fit over it. So I'm wondering if I have to buy an eddie bauer one, or if I should just get a draping cover?