Two problems related to battery cable have been reported for the 2005 Mini Cooper S. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2005 Mini Cooper S based on all problems reported for the 2005 Cooper S.
Parked the vehicle after a short trip of approx. 10 miles. Left car for approx 5 to 7 minutes. Returned to find smoke billowing from under the hood. Immediately started to unhook the battery cable. Got the battery unhooked and smoke diminished. Tried restarting car, restarted fine, but no power steering. Assuming that the power steering pump went up in smoke. Fortunately, damage seems to be limited to ps pump. . . Not sure yet if smoldering/smoke indicates any other damage under the hood or not.
I have a 2005 Mini cooper. The airbag sensor in the passenger seat failed around 66,000 miles. I was told that the passenger seat airbag and both door sensors had to be replaced along with the battery cable at a cost of $4000. 00. Sounds as if BMW still has real electrical problems in their cars and are sticking it to consumers to fix it instead of fixing these problems themselves. The car has never been involved in any accident.