The 6 speeds imo are not nissans best tranny. Dont know about the 350z's but the G35s at work were constantly being replaced. Hell, i GAVE one to Mattback just to get rid of it. That one was like so many other third gear grinders. the newer ones feel way different than the older ones, and we hevent had any problems with them. So i recomend driving an 03 Z or G then an 06 Z or G. Night and day. Oh, and if you buy used, definitely go to a dealer and get its maintenence history. Weve had many problems with having to REPLACE motors because a lack of oil changes on the VQ's. Seriously, do some homework on it. less than 4000mile LoF intervals, forget it.