My wife has been complaining that her 04 Cooper vibrates like crazy and seems like it wants to die when she's stopped at a light sometimes. It doesn't happen all the time but it does happen quite frequently she says. Only happens while car is idle and stopped.

Any clues??

 

Woops. Wrong board. 04's go to 1st Generation. Same shape (with some differences) but different innards.
Not much help.

There are a handful of parts that could contribute rough idle, gonna take some hands on trouble shooting to identify the culprit. Wish you luck on that.

My wife has a low center of gravity. If the seat isn't all the way forward she just isn't gonna be pushing the clutch all the way down. No problem bouncing the gas pedal to the floor......?????

 

Moved to the !st gen trouble shooting section, hopefully it'll get you more attention now.

Did the dealer ever update the software in the ECU since 2004? I seem to remember this being a fix in a software update, (but I've an 05 so I'm fuzzy on the details of your software version)

There are a number of thins that can cause rough idle, from as complex as ECU programming to as simple as just a bad tank of gas. Are you the first owner? How's the standard maintenance been? (oil changes on time, how old is the air filter, injectors, what octane rating)

 

This behavior is somtime due to a failure in the low speed for the radiator fan. When the high speed comes on the car will vibrate as if its about to shut off. If the fan is the problem the vibration will occur approximately every 7 minutes or so if you just let it idle.

Another cause can be a dirty throttle plate/bore; restricting the minimum airflow needed for idle.

Hope this helps and good luck!