How old are these cars? You usually take a bath on trying to resell economy cars unless you do a private sale and then find another private seller with a good deal on what you want.
Fwiw my brother and I were BIG kids, we were both 6' by about 12-13 years old, and our parents made do with an old pickup (short back seat) and things like an old Sentra, 87 Taurus Sedan, Volvo 240, etc. It's certainly more convenient to have larger vehicles with kids, minivans are usually the best, but it's definitely possible to make do with something like a 5-door hatch like a Focus.