I've a liftback Corolla (the one thats somewhere between a saloon and a hatchback) and it fits fine with the back seat down. Usually take myself, my bass, amp and head, acoustic guitar and acoustic guitarist with plenty to spare.
I have fitted it in a Corsa with myself, amp and girlfriend easily too. If you lean the passenger seat back you can lie it back on that with the pin toward the passenger foot well and the scroll in the air over the back seat. Actually very easy to fit in believe it or not. I was almost given out to by my teacher for even suggesting you need a big car for a double bass and it's true. We do have to think about the environment too (and ridiculous petrol prices!)