 After 51,000miles, my 2001 Frontier's AC would not blow cold air. i had it checked out at the dealer and the low end hose was leaking and was replaced,at my cost. After a few days, hot air was blowing again. Now, it's the evaporative cooler behind the dash that is leaking. This, I think, is a highly unexpected problem to occur on a car this new. I thought Nissans were very reliable, that is why I bought it, in the first place. 