I have to say I had a terrible experience with rustproofing as well since I had that sticky stuff on my car doors. Partly my fault for taking it to wal-mart, anybody reading this DONT TAKE YOUR CAR TO WALMART, unless you hate your car.
Multiple washing had minimal effect on getting it removed, I had to wait till winter was done as the snow probably washed it off.
Multiple washing had minimal effect on getting it removed, I had to wait till winter was done as the snow probably washed it off.