Well, I guess it would depend on how much it rained on it. Do you live in Seattle or Yuma, AZ?
If it rained a lot, then water could have gotten into something electrical, and we all know electrical problems are a royal PITA. Does there look to have been a lot of water in the car? Another thing...what was the plastic attached to the car with? Make sure there are no paint scuffs or marks from tape or something. And then it would also come down to how much they want for the car. If you can get it for next to nothing...then it would be more appealing than if they wanted not much less than a whole one. Keep us informed.