It's bugged me ever since I've owned the car that it didn't have an external thermometer - I always like knowing how warm (er, cold in Michigan) it is out. So I went out to RadioShack and bought a car thermometer which has three functions - inside/outside temperatures, volt meter and clock, and you can have them in any combination you want, since there's two seperate displays. Has lots of neat little functions like an alarm when it's below freezing. $20.
When I got to thinking about where to put it, I came up with an idea - since my aftermarket stereo has a clock on it, and the stock clock looks like it belongs in a bathroom in 1986, I should put it where the stock clock is. When I saw that it lit up green I thought it was an even better idea. And once I found out that when plugged into a cigarette lighter it lit up green all the time, I was convinced.
So I bought a used clock pod, armed myself with a Dremel, and made it from this:
And a dark picture:
It's wired to the stock clock harness and comes on with the ignition, just like the stock clock. The green backlight is on all the time, isn't too bright, and matches the stock gauges very well. I ran the sensor through the firewall plug and mounted it in the bumper:
Unfortunately it does pick up a little bit of engine heat when the car is running and standing still, but as soon as you get moving it seems extremely accurate.
As for mounting, there are a great many ways I'm sure it could be done. I originally used duct tape, which works for a while but eventually loses its strength due to the heat of the dash and the heater itself.
After realizing this, I switched over to this:
I bought it at Napa auto parts. Easy and fast to use, and extremely strong. Has worked great for me, and I'd imagine similar adhesives would work just as well.
Overall I'm pretty happy with how it turned out, and now I have a clock for my bathroom
Just thought I'd share.