Нашел
The 996 C4 "boot" space can fit a (rectangular) piece of luggage 22"x 14" x 10". Coincidentally, the Porsche "fitted" luggage "small trolley" in both aluminum and "ultralight" match these measurements.
The international airline standard for a carry-on bag is 22" x 14" x 9". Hence, all luggage OK for airline carry-on will fit your 996 C4 - and vice versa.
Please note that the space in the 996 C2 is slightly larger (22" x 14" x 15.75") due to the mini-spare stored upright, rather than the collapsible spare stored horizontally.
1 дюйм = 2.54 см