In the scene where Hudson visits Sarah's apartment for the first time, Sarah places the broken turtle on the arm of the sofa before Hudson calls her cute. In the next moment, we see Sarah say, "You think I'm cute?" while still holding the turtle.
When buying the new car, the salesman tells Hudson that there is "Four-point-two feet of cubic space back here." It implies that the trunk is only about a foot high, a foot deep and four feet wide (1 foot x 1 foot x 4 feet = 4 cubic feet)... a ridiculously small amount of space for any trunk.