I called them and they said that you can shorten the length of the door bars and rear bars, did not have any direct customers that came to mind for 318ti.
Yolo, I ordered it anyway. I talked with Rhodes pretty extensively and they said that the only components that need to be accurate are the front and top hoops so fingers crossed everything else can be cut to fit. Will know next week when its installed by shop and let you guys know if anyone is interested in caging their Ti.