On a hot day like today (98 degrees), if I come home and plug the car in to chart (car is sitting outside), shortly I hear fans kick on, I assume, to cool the battery pack. There is a fairly quiet fan noise coming from up front and a fairly noisy fan noise coming from the rear. Sounds like an unbalanced fan. A vibrating type of noise. This is a 2013 i3/REX. Anybody know if the rear fan is an easily accessible item or is it actually buried in the battery pack somewhere?