What it's gonna hurt? I mean, I can see the String drying out. But if you wax it good, wouldn't the heat melt the wax into the string thus protecting it? 100 degrees is not going to effect your limbs or riser. Sure I wouldn't make a practice of storing it in there for days on end. But short periods of time (8-10 hrs once in a while) I'd need to see some proof of it being damaging!

However, you may be able to regenerate your scentlok in there if the car gets that hot !?