I think the dealer was giving you a line of BS. A typical order time is 60-90 days, with about 75 being the average.
If you ordered on March 1st, the order probably went to Nissan the 5th because that was when open orders started in March. (Nissan only takes orders during a week or two each month) BTW, mine was ordered March 5th. If it was ordered then, it was built in April and will be delivered in May. Mine is due May 21st.
Ask the salesman to fax you the print out for YOUR order from the NNA computer system (
http://oms.nnanet.com/orders). It should show all the equipment, invoice, MSRP, build month, est. delivery date and VIN (among other stuff). If they will not do this, start raising hell. My salesman faxed me the sheet when I made the order to confirm they got the equipment right. That website will update when the VIN is posted (mine was just posted last week, so I doubt yours was done 4 wks after order) and give a del. date. I think the del. date may change depending on transportation. I've heard from others here that the del. date sometimes moved up as time passes.