February 26, 1999
By: Russ Caslis

In my old 1.9 Z3, I had the on-board computer which told all sorts of interesting things such as estimated range, average speed, and outside temperature. Call me strange, but with my new M roadster I miss that. I miss the 400 mile trips during winter in the dead of night with the top down, watching the temperature fall to below freezing, with the reassurance that yes, I was out of my mind.

On the Euro-spec M roadsters, they get an outside temperature gauge. According to rumor, it doesn't work that well. Besides, to add that to my US-spec M roadster would cost more than $200, which I don't have. I finally found a digital temperature gauge that met most of my needs, RadioShack part number 63-1023. They offer 2 different temperature gauges for cars, this is the better one (and more expensive, about $20).

The good things about this gauge are that it displays both the inside and outside temperature at the same time, it records the highest and lowest temperature, and it has a nice electro-luminescent backlight. On the down side, the LCD is hard to see from some angles, the backlight only stays on for 3 seconds when the button is pressed, and it uses batteries instead of car power. But altogether, it's the best one I've seen anywhere.

The first thing I did was add a black sticker to the front that covers up the "RadioShack" name. It's a small thing, but call me anal-retentive. Next, I went out and bought a radar detector windshield mount. I decided the best place for me to put the gauge was above the rear-view mirror, on the driver's side. I had to be careful about the angle I placed the gauge at, since from some angles it's hard to see. Once I had the angle figured out, I had to cut the detector mount down to the right size.

Next, it's time to do something destructive. Cut the lead for the external probe halfway between the display unit and the probe itself. You will need to attach some extra wire to make things work. The place I placed the probe was up in the front bumper, behind where the front license plate goes. I took the black mounting bracket that comes with the gauge, removed the rubber piece, and superglued the mounting bracket in place. Next, I connected some more wire to the probe piece and ran them into the passenger compartment.

In the cockpit on the passenger side, underneath the glove compartment there is a piece of plastic held in place by 3 plastic screws. Remove this piece of plastic by turning the screws a half turn and removing them, then the plastic piece slides out. You should be able to see a rubber grommet by the speaker grill.

On the inside of the engine compartment you should be able to see the other side of it. Run the wires for the temperature probe through this hole, you should be able to push the rubber grommet aside enough to get the wires through. I then attached one side of a plastic 2-lead connector to the wires I ran through the hole. Don't forget to use lots of nylon wire wraps to hold things in place in the engine compartment.

You can see (kind of) how I ran the wires along the passenger side of the engine compartment. Now it's time to remove the plastic covering the inside of the pillars. To remove the side coverings, simply "pop" them off. I would recommend using a screwdriver with the tip covered by a towel (to prevent marring the surface) and wedge it in the top, then pull down. These should come off with a nice "pop". You need to do both sides. Next, you need to remove the top frame covering. The clear plastic around the dome light gets scratched very easily, so please be careful (it's white plastic under the paint, so it really shows when it's marked up. The clear plastic pops off, try prying from the drivers side - that side is supposed to come off first. Then remove the light bulb assembly, it also pops out. Once again, be careful not to mark up the paint. Next, remove both visors, you will need a torx screwdriver. Then remove the one remaining torx screw that holds the top piece in place, it's behind where the light assembly was. Last, just pull up to remove the covering.

Now it's time to start placing things where they go. Use some superglue to attach the gauge to the radar mount, and be sure to let it dry thoroughly. Place it on the windshield in the proper location, and run the wires where they would need to go (you will have to attach more wire, the gauge only comes with 10 feet of wire and much more than that is needed. You will be running it along the top of the pillar and down the sides, next to the glove compartment. Once down there, attach the other end of the nylon 2-lead connector.

Now, just plug the connector in, replace the plastic piece below the glove compartment and put the molding back in place along the pillar and you are all set! Not quite as good as a factory installation but it does the job.