Tacoma frame questions

I’m trying to find a Toyota Tacoma anything 05 or newer. The question I have is about the frames, my brother has a 2010 4 door that has a single channel frame for the bed and shows no rust. I have looked at 3 extended cab trucks now an 06,07, and 09. The 2009 had rust up near the front tire, the 06,07 had frame rust behind the rear tire if your looking at it from the side. Where it was rusting from the inside and separating the 2 parts of the frame. Is that just an extended cab thing or just a new design they went to in 2010 like my brothers? Thanks guys

 

yes but the ones I have looked at have a big C channel and then a C channel inside of that one. My brothers is only 1 single C channel. His however is a 4 door and the ones I have seen with the double channel are extended cab. That’s why I’m wondering if they went to that style in 2010 as I have not looked at one over 2009

 

Yea that would describe my brothers, that’s why I’m confused as to why his is different than the extended cabs I’ve looked at.