Aside from risk of theft, I think it's fine. If you're insured, then what's the problem? I assume you have a camera bag with insulation so I don't see the risks of heat - you won't be leaving your camera in the open on your dashboard (or will you?)
The more you use your equipment, the better value you are getting out of it. At the end of the day they are just depreciating items (yes, even lenses although at a slower rate)
To be fair it's all personal preference. I take my cam to the beach whereas my friend is paranoid about sand/salt/corrosion/theft.... I could go on. Meanwhile I'm the one with great beach pictures.
