Our 2015 Mini S had the rear wheels parked on a sloped driveway for an hour with the emergency brake on ,but in neutral. Then the car rolled down the driveway and hit a tree and damaged the rear quarter . Has anyone else had a problem with the emergency brake?

Nope.

Next time when parking on a hill try this. Hope it helps. I remember having to learn that in driver's ed back in '62. Our stick shift car was an Army surplus '51 Chevy sedan. Had the mil-spec plate riveted to the dashboard...quite an adventure.
Did you keep the brake pedal depressed when you set the parking brake? You can feel a difference in setting force either way and maybe the rears didn't get set as tight as they should.

Why would you park a car in neutral, even with the e brake set. A car should always be parked in gear when kn an incline (or even on a flat surface). Just good practice.

X2!!! Have been driving for nearly 55 years and the parking brake has always been the last part of any shut down sequence. Even if you do it on level ground just to keep the habit it won't hurt a thing. Kind of like wearing seat belts, just a good habit.

Just my two cents but actually the PB should be the first part of a shutdown sequence. Come to a stop, foot brake on, clutch depressed. Set parking brake and release the foot brake to make sure PB has held. If you are on a hill and the PB doesn't hold you want your engine to still be on so you can correct. Shut of engine and release the clutch with gearbox in gear. If you shutdown first you may leave the car in gear prior to using the PB which is not the correct sequence and you will be loading the drivetrain (especially if on a hill).


On another note if you want to check the PB. Engage the PB to the detent where you normally place it try to move the car in first gear by loading the drivetrain. If it doesn't move you should be good, if you roll probably needs adjustment.

the e-brake is 'mechanical' ... actuated by cables .... it could be out of adjustment ... how many 'clicks' is engaged for you? I get 3 or 4 when I really yank it.

A problem that I HAVE seen is one side failing while the other works - two cables attach to the handle, one for each side (this way on GEN1 and 2 anyway). One cable could break or get dislocated from the caliper. Obviously your e-brake force would be reduced by 50%, but thing feel right at the handle. Set the e-brake and jack up each rear ... try to turn ...

p.s. ... a 15' .. aren't you under warranty? (same in Canada????) With an e-brake failure, covered by warranty, I'd look for the body damage to be repaired as well! Dunno I'd succeed but worth a try. Maybe even a case for the insurance company to pursue ....

Of course MINI is gonna say: you did not engage the brake properly, did not park in gear, and unless you DO find something broken .... nothing on their side was wrong .... so: driver error