I wouldn't worry about it.

 

Some Nissan techs say its normal.... blah... just means Nissan is too cheap to fix it. It's not a safety issue. I don't think it will hurt anything else...

BTW the speedometer will do it too, it just seems to be less sensitive for some reason. Only happened on hot days for me, 95 deg F +. Still have the digital one though... which I use anyway. The analog one is kind of hard to read I think.