2500 sub suspension clunking

2005 8.1L 2500 suburban LT with ride control. been noticing lately the steering tends to 'wander' a bit... more noticable at highway speeds... don't know if these things are related but, with the windows down, driving around city, the suspension really clunks and bangs when going over bumps... this is my first 3/4 ton vehicle... but it seems a $50k+ vehicle shouldnt sound like a garbage truck driving down my street

Look for something loose in the suspension. Maybe shocks or bushings.

dealer installed dampeners on rear leaf springs under warranty. fixed the noise problem...