Nuse is right. IMO there ain't no stitch of Rx-7 or 944 in it. The real-life Starion may have alluded to the porshe 944 a bit (or vice versa) as they were both introduced in 1982.
The Rx-7 is in a league of its own, though. I can't even consider it.
It's like comparing an engelmann spruce tree to a sitka. Then you Rx-7 people come along and say Oh, look! a fir tree looks just like em! The LFS Christmas tree must be copying all three!
You see, one thing you must understand is: if the similarity is there in real life, it doesn't mean the XR is copying both! It's also possible that any differences from the Starion are unintentional, or merely to keep from being sued by someone.