The built-on running boards (these are not an add-on feature to the vehicle, but came standard on all qx-4s) have brackets and a tubular steel support beams that support the weight of any passenger stepping on them to enter the vehicle. the support beam and support brackets have entirely rusted away; there is little to no other rust on other areas of the vehicle. a local body shop identified and notified the owner of the danger associated with non-supported running boards. a consumer could easily be injured if stepping on the running boards to enter the vehicle and having them collapse. the injury certainly could be more acute for elderly, disabled, or children in the event of a collapse. the tubular steel support beams and brackets have no rust inhibitor on them while the other metal sections of the running boards were coated with rust inhibitor and show no rust. there was a design flaw either associated with the type of metal used or a lack of rust inhibitor on the parts that have disintegrated. the cost to replace is quite exorbitant and the replacements may have the same design flaw. the short term solution has been to entirely remove the running boards off of the vehicle to eliminate the danger. this makes for a tall vertical step-in, but is less risky then the faulty running boards. *tr