I get lots of exhaust fumes inside my 84 K5 when I am parked with the windows rolled up. I notice the fumes as soon as I park the truck with the engine is idling. I don't notice any exhaust odor when the truck is moving. No rust holes anywhere... Southern Truck. 8 month old exhaust system from the engine back. Plus, I had the mechanic re-check for leaks this week. Could the fumes be coming in around the tailgate? The stock tailgate gasket looks OK. The new exhaust turns out to the sides like the original stock system. Any other places to check that you could recommend?