I just bought this device yesterday. Here are some questions

1) I travel outstation a lot. The salesman that sold the K100D told me that better to unfix the lens when the camera is in the bag behind the car. Can I fix the lens all the time or do I need to unfix it?

2) There are 2 packet of those thing to absorb moist in the camera bag. Is it harmful to put it there? Will it melt in heat?

3) How much heat can the camera take? Sometimes I drive 5 hours one shot in the middle of the day. The camera bag is at the boot and it could be hot. Would it be a problem?

4) Pentax 18-55mm F3.5-5.6 AL Lens. Is the distance of the zoom equivalent to 3x Optical zoom?

5) Pentax SMC-FAJ 75-300mm F4.5-5.8 AL Lens. What is the equivalent for Optical zoom? How to count?

1) You can left the lens attached to the body, depending on what type of camera bag you have. If backpack type, it's better to take it out. If those square type, I believe your zoom lens can't fit in, so most of the time you'd have your kit lens attached, like mine.

2) Shouldn't be a problem.

3) Leave it in your car's cabin and let it enjoy the aircond. But do take note of this. Once you took the bag out of the car, into the hot sun/temperature much warmer than your car, DO NOT take out the camera immediately. Let the temperature increase on the camera first, else moist would be formed due to condensation. (Actually, this should've been stated in your user manual)

4) Forget about the xx thingy.

5) Basic calculation is, take the longest focal length divide by the shortest focal length. Eg: 300mm / 75mm = 4x. But the 4x only applies to this lens, as in the magnification from shortest focal length to the longest. This is my understanding, correct me if I'm wrong.

Enjoy your new toy!