I have a 2010 Clubman and the barndoors pop open if I forget to lock the car. It happens when I am at a stop or parked. It happens both when the key fob is in the ignition and the car is turned on and when the car if off. Could it be the barn locks?

 

You have a sunroof?

This started happening to me also one morning last year.

Later that morning I discovered water pooled in the passenger side's footwell.

A LOT of it.

Turns out drains from sunroof gutters had come apart (known issue, why some dealers won't order vehicles with sunroofs anymore) allowing rain water freely draining into body behind interior panels, and affecting the electronic 'brain' thing on that side of my '13 Clubman.

There's another 'brain' on the left side also, serves similar function but to different systems. Water intruding on either/both are Not A Good Thing At All.

If you have no sunroof, it's still likely something with those two brains making your door pop open. Sometimes mine opens when I have my key fob in a pants pocket and I bend over or crouch. Pressure on the fob opens the door. I wish there were some different means by which this 'feature' could be coded out so it doesn't happen when my Clubman's sitting on the driveway in a downpour & I inadvertently pop the door while in the garage doing something....