Re: 1998/1999 F150
I've got a '99. I really haven't had too many problems with it! Mostly just maintainance issues... Have they done proper maintainance?
The only thing I can say is that I have put mine WAY off the road and have gotten the body out of shape. The 4 doors are a major factor of body rigidity. Because they are doors and not a fixed body, they do afford a small amount of play when you torque the body...as when going rough off-road. Check for body parts that are wrinkled or bent around where the doors close to the body. Also check to see that all the doors open and close properly.
Also, check for signs of being wrecked. People will not tell you the truth when it comes to the almighty dollar!