get the new one..
you can get those concave convex whatever wheels you like anytime later and wrap them with tires which is much better than nitto
backup camera?? seriously?? I drove a 350z for 4 years and 370z for 4+ years and never feel the need of a camera... especially with a chic on the passenger seat... c'mon, drive like a man and forget about those aids...
used car... you never know what problem do they have and how did the previous owner torture it.... maybe that's why he/she has to sell it so quickly...
Get The New One...