What does this mean? compass installation instructions

What does this mean?

http://www.thecompassstore.com/v2000faqs.html
"Can I hardwire my unit to my vehicle using the 12 volt adapter?
We do not recommend using the 12-volt adapter to hardwire your unit,
as hardwiring may require the removal of the fuse that protects the
unit from exposure to power surges. Altering the 12-volt adapter or
the unit voids your warranty."

I'm guessing the 12 volt adapter is a cirgarette lighter plug, but
maybe not.

Why would hardwiring require the removal of any fuse, including one
"that protects the unit from exposure to power surges"? Just get an
inline fuse holder and put in the right fuse.

Why would anyone use a plugin instead of hardwiring something, unless
the car was a rental?

And elsewhere (maybe on another site also selling PCI compasses) I
think they sell hardwiring kits. The kit is just the right plug on a
wire, with an inline fuseholder, for 20 dollars I think it was.



Anyone have experience with adequate car compasses? I had a
flux-gate compass from Radio Shack and it worked well for 7 years.
But in this car, the needle seems frozen, regardless of the
adjustments I made to the two potentiometers.




Here's anotehr interesting line from the same page: " We recommend the
door jamb of your vehicle on the rubber stripping [to mount the
temperature sensor]. The inside temperature can be affected by direct
sunlight and the temperature sensor by your vehicle fan."

If you mount it on the rubber stripping of the door jamb, it won't
measure either the inside temperature or the outside temp, will it?
It will be somewhere in between.

Remove NOPSAM to email me. Please let
me know if you have posted also.
.