Here is where I mounted mine.

 

My $.02. I happy with the Ultra-Gauge and it is probably the best $70 spend. The only big issue with it is that it only works when the engine is running. If you (like me this weekend) got a problem and the engine can't be turned on then you wont be able to read the codes from the unit

 

Here is a pic of where I located my UG. I also have one in my wife's D2, but she wanted it on the other side of the instrument panel. So, it's located just above the fog light switches on the left hand side of the instrument cluster. Both mounting positions are easy to see while driving.

I used 3M double-sided tape to mount the bracket. UG is easily removable and I can still access the "up/down" buttons while the UG is clipped into the bracket.