During the landing at a private airport, the pilot "landed long to avoid [a] dip in the field..." With the flaps positioned at 30 degrees, the airplane landed on the grass runway (2,000 feet long by 90 feet wide). The pilot felt the airspeed was too fast to stop, and he aborted the landing and attempted to execute a go-around. He retracted the flaps and applied full engine power. He "jumped the airplane off the grass" and tried to get the airplane to clear power lines. The airplane stalled and the left wing impacted another set of power lines. The airplane impacted several vehicles in a used car parking lot and came to rest on top of three vehicles. The pilot sustained serious injuries and the passenger sustained minor injuries. According to the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1) Recommendation (How could this accident have been prevented) section, the pilot reported, "Land on numbers, or make go-around decision if that is not possible on short fields like this one..."