As I was pulling slowly into a parking spot in a busy lot that serves a lot of small businesses, my Subaru suddenly accelerated forward, over the concrete parking bumper and raised sidewalk area, and into the side of the building. While I was uninjured and had no passengers in the vehicle, the car sustained damage to the apron and tire area on front passenger side of the car. The airbag did not inflate. Tiling on the exterior of the building was impacted, but not greatly damaged, and I had been able to avoid the plate glass entry to the business. A few customers were greatly alarmed by the Subaru's proximity to their lunch tables by the windows. I was able to put the vehicle into reverse and carefully move it off the sidewalk. I exited the car and went in to share my insurance information with the empathetic employees and manager of the business. I was able to drive my vehicle about two blocks to a larger lot, so that the towing company my husband contacted could access it, but not for several hours. The vehicle was taken to an auto body shop where it remains until they are finished with it. The claims people seem to have reached the conclusion that since I was driving, I must be at fault in this accident. I immediately, and still, continue to think over that incident, trying to determine how parking carefully and without distraction could turn into such a collision. I believe that I am not to blame. In reading the reports that have been made to your agency on Subarus