Don't let these guys make you feel guilty for buying the car you wanted to buy. There is principle in Total Quality Management/Total Quality Control ("TQM" or "TQC") to which I am sure Nissan subscribes in one form or another.
This principle addresses a concept called "Design for Use." It means that the engineering of the vehicle should be designed in such a way as to meet expected driving conditions. It is the manufacturer's representative's responsibility to ask you, the customer, how you plan to use the vehicle he/she is trying to sell you. If he/she didn't ask you this fundamental question because selling the car was more important than meeting your needs and expectations, then it's his/her "bad," not yours. If the literature that advertised the vehicle or came with it did not specify that it should not be used for extensive driving in high-traffic conditions, Nissan's "bad," not yours. Really, do you believe driving in Tokyo does not involve stop and go traffic? Been there, done that! It does! Beats New York IMHO.
The manufacturer should remedy their mistake, not send you off to pay for the repair.
As one of Japan's leading auto manufacturers, I am sure Nissan follows TQM/TQC practices, and I'm sure that if you persist you will "win." My argument with Lexus about the operation of the passenger-side seat in the LS400 I purchased in 1991 revolved around the salesperson's statement that the passenger seat in the front "operated just like the driver's seat." This statement was false. When we took delivery of the car, my wife could not adjust the seat up and down. Consequently, she couldn't ride as a passenger in the foothills of the SF Bay Area without becoming nauseous. After my persistence, Lexus actually offered to take the car back and fully refund our money -- purchase price, taxes, licensing fees, etc.
I loved the car, I proposed another solution which Lexus implemented without cost to us. Lexus's action is what Japanese TQM/TQA is all about. Go for it.