It's difficult to address this question, as it seems like a lot to try to catch you up on. First, the US military no longer uses Jeeps, like the ones you crash landed in rice paddies, and has not for over 20 years. They were replaced by the "Hummer" (H1) in the early 80's (more here:
http://en.wikipedia.org/wiki/Hummer). The civilian Hummers now come in three flavors (medium, large and extra large) and are made by GM (not Chrysler). Chrysler still makes civilian Jeeps, and has now greatly expanded their lineup (pretty much doubled it) in the last few years.
I am guessing that you may be referring to the new Chrysler 300's when you talk about boxy looking cars, but they don't really look like a Hummer. I am pretty sure the no American company has taken design cues from a Citroën, as they are usually ugly enough to make people appreciate a Pontiac Aztek. edit, I just googled the BX and I would not use it as an outhouse.