From what I can tell, about 2/3 of them still exist. Some in better shape than others Salt is a problem here yes. We use more salt than sand here. So yes, rust is a big problem. In fact, when we got it back in the day, you would not believe how rotten it was. I mean, this is beyond ANYTHING I have ever seen. We couldnt find anything solid what so ever. The underside of the tunnel, was so rotten that I stock a screwdriver up into it, and with 2 fingers walked all the way down toward the rear with no resistance what so ever. It was completely gone. And yes, that is the front of the frame that has a huge rust hole all the way around the top. I tried to zoom because I dont have better pictures than this right now.