1.) Dont use your iPod for music in a car with even a decent system unless you are using 256k +, 512+ preferably. Kinda working backwards if you do.
2.) Depending on what iPod you have and when it was made depends on the hardrive it uses, find out what harddrive your iPod uses and look up its maximum reccomended operating temperature.
3.) Tint your windows, sound deaden your vehicle, and put acoustic fowm in your doors...not only does it improve the responce of your system but it keeps your car cooler in the summer and warmer in the winter for longer periods of time.
Even when temperatures are reaching into the 100's here in FL i can leave my truck in the sun all sealed up for 2-3hrs come out and its not much hotter inside than out, espeically if i was running the air before i got out of it. I only have 10% on the rears and 28% on the sides and a strop across the windsheild. Maximum legal in FL.
In the winter i have gotten my truck nice and hot before i went into school, been in school for 2 periods before i go back out to my truck (~4.5hrs) and it still be comfertable inside...that is even on days that it never breaks into the 50's.