What about something like this stuff on the shoulders are tire that are conected together with straps the thing at the stomach is a tire also without texture it doesn't look good.
Even untextured, I can really see the potential in that model - I'm pretty sure if you carry on with it, it would look both very good, and very Fallout.
There's an old concept art for Khan tire armour
here, which is possibly worth a look, though to be honest, I think I prefer the way you've done it.