If you hot wax every time out, then you can use extra wax and leave it on your edges and scrape once youre at the hill. This is the best way to protect you edges that i know of. I dont reccommend carrying your skis on your roof unless you have one fo thsoe closed cases, there is no way to save your equipement from that kind of abuse, especially if you are in the north east where there is always salt on the roads... out west there seems to be a use of more sand than around here. Also, make sure that you dry your edges and skis thoroughly after every use. and then let them sit out (seperated) as soon as you get them home. If you use a bag, make sure that the skis arent cold when you put them in the bag if it is going into a cold place - obviously, and also make sure the skis are dry. Dont leave the skis in the bag either. As long as you are taking these precautions you shouldnt have rust on your edges. Once the skis are fairly dry the best cure i know of is the wax on the edges. When i transport my skis for races i usually keep a thick coat of wax on them just in case the load get pushed around. Try that, it cost quite a bit in wax... but if it saves your edges i think its worth it. The Swix Alpine training kit from reliable is pretty inexpensive if youre looking for all-purpose wax. Its about $50 with shipping, and you get 900g of all different waxes... all CH though. If you like LF and HF, then leaving a lot of wax on your edges requires a lot of $$ or friends in high places, who will give it to you (teams, race rooms, etc).