This past summer I ran into a ditch on the passenger side with my volvo. The only noticeable problem was that the control arm on the passenger side was bent badly, so i replaced it. Then we brought the car to have it alligned and the mechanic said that the other control arm on the drivers side needed replacing. That was fixed. The car was still vibrating so i had the wheels balanced and the mechanic told me my rim was bent, so i picked up a rim from the junkyard. Then I had the tires rotated. The car now drives smooth but has a slight vibration in the steering wheel at speeds of 70 to 80mph and up. Any ideas on what could be the problem or something I should replace?