I have a 2011 mini cooper s that i attempted to install an alpine 73bt-ute stereo in and while about a week after my car starting going crazy. it would randomly shut off while i was driving without warning, when it did shut off the windsheild wipers would come on and not turn off untill maybe 5-10 miniutes later when the car started up again. when intsalling the harness i noticed that there was no adapter for the steering wheel controls so i left the connection hanging, but would that cause all these problems?

 

In the past the flimsy connector on footwear module misbehaved resulting in weird electrical issues for me.
I was installing LED fog/running lights kit and needed to tap in to one of the wires going into footwell module. When everything was installed, I lost my lights, the hazards would not work, and everything behaved weirdly.
I thought I have wired something wrong. Turned out to be one of the connectors on footwell module. After reconnecting it everything works as expected ever since.