Hi there,
We are using 2 strollers (Peg Perego P3 & Maclaren Triumph) and they both fit in the trunk without any issues. Here are the links for both of them.
http://www.pegperego.com/page....&cl=N
http://www.maclarenbaby.com/us...d=492
I am not quite sure about your concern as you've mentioned "blocking the rear window". Are you planning to put the whole stroller in unfolded? But if the Chicco can be folded then compare the "folded" dimensions with mine from those link and that'll give you a better idea.
And if you're still worry then just go to the store (I'm sure they have some demos/floor displays) so you can just test fit it yourself.
Hope it helps.