Looking over my newly aquired 04 4runner, I've noticed there are several surface rust on the undercarriage, and especially the tow reciever, I was going to wire brush the surface rust of and spray it with black primer, would this be a good idea or should I just leave it alone? I live in NY and when it snow they throw down a lot of salt on the roads... I rather be safer then sorry as I plan to keep my car for at least 7 years...