I do not know what caused this. Here is what happened. While parking the car suddenly accelerated, over the curb, on the sidewalk narrowly missing the building because I turned hard right to avoid the building and I was able to brake to a stop glancing off a concrete pillar. We could have been hurt crashing into the wall/windows, anyone on the walk would have been hurt & anyone in the store could have been hurt. The car was towed to Hatchette Hyundai-East waiting to be looked at. There is no police report because it was private property and no damages except to my car. No warning lamps or messages. I remember 2 previous incidents that happened recently. While driving in normal city traffic, my passenger asked if I had speeded up? It was morning traffic, so I didn’t really think about it. Later that day while returning home there was a weird thing that happened. Again, in traffic, the car engine did something weird, but I thought it was the car reacting to the car beside me being too close. It was like it downshifted, slowed down and then resumed normally. The only other time I had any problem was on May 9th near Lawrence, Ks. The car began vibrating and felt like it was going on rumble strips when I accelerated and did not get up to speed. If I let off the gas it quit. I had the car taken to McCarthy Hyundai-Lawrence, Ks. They diagnosed an issue from the computer codes and completed repairs having the car from Monday until Wednesday.