This is a grave safety concern on hills! Right after the purchase of the brand new Acura TLX 2015 9-speed transmission from Acura of Bellevue, WA, I encountered problems with unintended accelerations upon pressing the brake on down hills. When downhill, if I pressed the brake, both the RPM and speedometer swing upwards and the car rushes forward with acceleration roars. RPM can immediately swing from 1700 to 3000 and speed can jump from 40mph to 45mph - when your foot is still on the break! It almost got me into an accident. It took several pressing of the brake to slow down the car on a slope. I went back to the dealership immediately and their technicians easily reproduced the problem on a slope. In fact they already knew this issue with 9-speed transmission, along with all other transmission jerking issues. The technician verified that this car upshifts during the break and even opened an internal Tech case to Honda, but they couldn't fix it. After several times dealing with dealership without the issue getting fixed, I requested a return of the car since it's a grave safety concern to me as I live in a hilly area, but their managers who apparently care nothing about public safety, kept arguing that these are "standard characteristics of the 9-speed transmission". If they keep treating public safety concerns this way, another class action will be just around the corner. Every owner should be very aware of this issue- it happens often on down hills, can be very unexpectedly, and not obvious on flat road.