While the S4 is pretty new, its time to do a clear urethane wrap of the bonnet and leading edges. We can get big stone chips here when highway driving thanks normally to trucks or other cars straying into the hard shoulder a bit. I've done this before and it works very well. I've got a good mate who owns a tinting business and we'll do it either this week or next. You can't see it and its just about indestructable. Saves your paintwork, and bird poo wipes off. Do you guys use these types of products? I've heard things mentioned here but not sure if this is the same approach for similar issues.