PackerFan

I've posted elsewhere that I'm currently looking at an '04 G500 with 3X,XXX on the clock and is a CPO vehicle. The vehicle looks great, but I noticed one thing that bothers me a little and didn't know if this was anything to worry about. The underside of the hood (where the rigidity "ribs" are located) has what appears to be surface rust. Anyone else notice this on there G's? Since the vehicle is past the new vehicle warranty due to time, is there an extended rust protection warranty (like 5 yrs/60 miles, etc...)? Would the CPO cover this if there is no extended rust protection? Are there other areas of concern that I should check out while the dealer has it on a lift? The truck does have the steering wheel vibration, and after reading numerous threads within this forum, I know what to tell them. Any feedback on the rust would be appreciated.