Undercarriage rust on Nissan's common? Looking at a 2001 Pathfinder

[stioc]

I'm in SoCal and I've been looking at 4x4s, mostly Monteros, Xterras and Pathfinders. What I've noticed is that the Nissans have quite a bit surface rust/pitting on the undercarriage components, mostly the rear axle/subframe area. At first I thought maybe I'm running into trucks that are not well taken care of but after looking at 2 xterras, 2 pathfinders and 3 Monteros it seems to me the undercarriage of the Nissans is not as well coated?

More specifically I just looked at a 2001 Pathy SE that's one owner, super clean, I'm 99% sure I'm buying it. I checked all the usual things, oil condition, transmission slippage etc, ran it through all the 4x4 gears in the parking lot, everything works except the clock. The only thing that bothered me was the light surface rust/pitting in the rear axle/shocks area. The owner said they've taken it on the occasional skiing trips but it's always been an urban family car and has always been in SoCal. What say you guys? Is there anything else I should check for before pulling the trigger on it?

[stioc]

Oh I just remembered, all these trucks have been near the coast so it could be the salty air from the ocean. But only seems to affect that rear area in my observation.