Have you seen the steering wheel from the Cobalt? the plastic bag like material used for the shifter and ebrake boots? The plastic dashpad with fake stitching? Cheap plastic abounds... and it does irk you after awhile, if the flat seats don't enough. I had no probs with the nav/radio... it seems most 'vette owners also complain about the nav as well, but I never used the nav, nor do I listen much to the radio, there's no issue with the engine soundtrack. And only my bikes have given me a more brutal, visceral acceleration experience than the Z06, but normal driving, it feels like you're manning controls to a very heavy vehicle, almost truck-like. (despite it being only ~3170#) The seat in the E92, is truly one of the most supportive I've experienced and I would expect the 'visceral' component to go up after I get the Corsa exhaust.
Current stable: 2013 GT-R Black Edition, 2012 Audi A3, 2012 Frontier Crew Cab Pro4X. (recent: E92 2010 Jerez Black M3 6MT, 2008 Corvette Z06, 2005 Ducati 999bp, 2006 X5 4.8is, 2005 FX45, 2005 S4, 1999 540i6)