The blind spot, particularly on the driver's side is very bad in the 370Z - I got spoiled in my 350ZR as there was no blind spot at all!
While I haven't gone out and bought one yet, I'm going to buy a small dome/fish-eye mirror to put on the driver's side to help...other than that, the only thing you can do is to be very aware of the traffic around you before changing lanes...you just kind of have to assume there is a car in your blind spot until you prove otherwise!