Pros:
1. Easy installation.
2. Accurate temperature readings when the sensor is placed at the right place.

Cons:
1. Back light is too dim. At night you have to get as close as one foot to see the digits.
2. The silver cover is too shiny. You can see its reflection in the windshield. It should be a dull color like the dashboard.
3. Expensive for what it does.
4. You would hope the thieves are smart enough not to think it is an expensive GPS unit.

Conclusion: This product is not worth buying. It has been on the market for at least two years, but you don't see the manufacturer making any improvement on things such as the back light. A Gentex auto-dimming mirror with compass and outside temperature has better value.

Update on 11-5-2006: One month after installation the outside temperature sensor went dead.

Update on 12-27-2006: Finally received replacement unit from the manufacturer. Customer Service was not very responsive. 2 stars

This compass wasn't easy to set up. First, I had to buy a tiny Phillips screwdrive to open the case in order to insert the battery for the temperature transmitter. My husband, who is in construction, didn't have the correct screw driver in one of his many tool boxes. In order to attach the thermometer transmitter, I had to lie down in a driveway and search for a place to attach the device under the front of the car (if I were younger, this might have been easier). After getting this accomplished, I discovered that the backlight display on the compass (which has an easy to open battery compartment & an optional cigarette lighter power source) doesn't really work in the dark. During the day it is a reassuring device. I have yet to find out whether the icy roads warning device will function during the upcoming winter months. A rather pricey gadget. 2 stars

My original goal was a replacement rearview mirror with Compass and Temperature but installation would have been very complicated involving major disassembly of the vehicle. This unit performs as well, if not better and installation was a breeze! The compass actually reads out in degrees and appears to be very sensitive. The wireless remote temerature sensor was easy to install (many choices of location) and works perfectly. The new mirror that I was considering would have cost more than twice as much as this unit. I am very, very pleased. 5 stars

My unit was really easy to install ... no wires just suction cups for the main unit and no tools required for the temperature unit. I drive mostly during the day so I like the unit, but those who do night driving cannot see the DIM LIGHT.
I had to remove unit in order to pass the VA state inspection.
In cold weather, the temp guage sometimes does not work.
Also, about the temp sensor ... If you place it too near the hot parts of the radiator it will not be accurate while driving in town or when stopped. Behind the front license tag is great ... I put an old license tag under the new one and drilled holes to hold the temp sensor. That method works great.
I really like the automatic calibration feature. 4 stars

I really love this compass. Literally easy to install, easy to set up. (you still have to drive your car 360 degrees)
Temperature reading is very accurate. Overall, I think I made the right choice.
A couple of problem- It's hard to read under bright sun light. LCD is not bright enough, it's enough to read direction/temperature, but needs to be brighter. DC power cord is too short. I mounted compass next to rearview mirror, and the cord is blocking radio/ temp control access.
If you don't care too much about those problems, and you don't want to have wires dangling around by you, this is the right product for you. 4 stars