Any idea's about the illuminated dot found in the fuel gauge? See the annotated image below. It was not part of the fuel gauge in our '07 MCS Hardtop and there is no reference in the CM Owner's Manual.

 

The consensus seems to point to the dot indicating the "full" reference mark for the fuel gauge. This may better help one determine the fuel level when glancing at the gauge at night. And, while this doesn't make a lot of sense on the windmill-style fuel gauge (as you have), the logic becomes clearer when the arc-style fuel gauge is viewed on the nav-equipped MINIs at night:

 

I have wondered too as it has never gone out for me...always lit. My MA didn't know either.

 

ahh the infamous fuel dot. so much mystery. silly little thing...

 

Hadn't noticed that, though since I've only test driven a CM, fuel level never really was of importance.

Koopah's assertion that it is for judging current fuel level vs "full" makes the most sense. I guess it's one of those things that MINI deemed unworthy of a mention in the manual.