If you're set on getting a Celica, definitely look for one with a sun/moon roof, as they offer an extra inch or so for your height.
The back seat is cramped for anyone taller than 5'4". Don't expect anyone to enjoy sitting back there for longer than quick trip to the store or to school. With your height, your driver's seat will probably be pushed all the way back, not leaving too much room for anyone (with legs) to sit behind you
Honestly, about 4" of leg clearance if the front seat is positioned comfortably for the driver.