I (hate to say it) leave mine in the vehicle all the time. I leave directly from my normal daytime job to most of my shooting spots, and it has to stay in the car. I do crack the windows there though, however the bows still heat up quite a bit. I haven't had a problem. Gibblets 452X strings don't seem to have any problems either with the heat, this is a common problem when bows are introduced to extreme temps.