According to Car Top Mook (magazine)--recently brought back by the Missus--the trunk dimensions are:
A. Rear Door Opening, Height: 90cm (35.4in)
B. Rear Door Opening, Width: 118cm (46.5in)
C. Trunk Length, Rear Seats Down: 164cm (64.6in)
D. Trunk Length, Rear Seats Up: 78cm (30.7in)
E. Trunk Width, Between the Wheel Wells:102cm (40.2in)
A. The trunk is both deeper and higher than the Rear Door Opening.
B. Widest point.
C. Don't know if front seats are foremost or backmost (or, somewhere in the middle).