Old EMs will fit in a Chevy Sonic hatchback, as shown. Can't speak for modern machines, too close to call.
Added over 6 years ago:ADDENDUM: I've moved approximately 10 different EMs in my Sonic with no problem -- and then I finally hit a snag when I picked up a Far Out. Far Out's backbox -- and some other mid-70s Gottliebs' too -- is 28" tall x 28.5" wide backbox. I was unable to fit this in the Sonic hatchback using my standard packing method shown in that previous post; the backbox is too tall, I couldn't stand it up.
It may still be possible, though it might require uncomfortable/unsafe driving positions and/or partial removal of the back seat. I had a friend with me at the time, so when we couldn't get it to fit, we just split it up between the two cars (one took backbox, other took lower cabinet).