Here is a good one for ya. I have a 02 MC and I found the battery dead after the car was parked for a couple of weeks (traveling) so I hooked up with battery charger and after an hour everything seemed to be fine.
Now at night the dash lights seem to flicker on and off with the engine running ONLY, if the car is not running the lights are fine so I can't think of anything other than the battery to be the issue.
Should I replace the battery

 

Is it the original battery? If so, it's way overdue for replacement. If not, it may still be the culprit. Mini's are sensitive to weak batteries and act up in all kinds of strange ways. Take it somewhere and get it load tested (many parts stores do it for free).
-skip-

 

Thanks Skip. I replaced the battery but still same issue.
Anything else I might look into?