I can think of three possible solutions:
1. Instead of hiding the key fob in a magnetic key box under the fender.... Hide the key fob in another location nearby. (Under a rock somewhere.)
2. Take the battery out of the key fob. Hide the fob as any other car key... Use the fob mechanical key to open the door and insert the key fob into the emergency start slot in the center dash compartment to drive home.
3. Buy a small waterproof case like this one and keep it with you.
http://www.inanycase.com/cellphone/1020-IAC-AQUA608.html
http://www.ebay.com/itm/Magnetic-Ke...068?pt=LH_DefaultDomain_0&hash=item23499bd64c
http://www.yorktownindustries.com/P...of-case-that-holds-your-small-valuables..html
1. Instead of hiding the key fob in a magnetic key box under the fender.... Hide the key fob in another location nearby. (Under a rock somewhere.)
2. Take the battery out of the key fob. Hide the fob as any other car key... Use the fob mechanical key to open the door and insert the key fob into the emergency start slot in the center dash compartment to drive home.
3. Buy a small waterproof case like this one and keep it with you.
http://www.inanycase.com/cellphone/1020-IAC-AQUA608.html
http://www.ebay.com/itm/Magnetic-Ke...068?pt=LH_DefaultDomain_0&hash=item23499bd64c
http://www.yorktownindustries.com/P...of-case-that-holds-your-small-valuables..html