It's not exactly the Denver area but give Prestige Chrysler Dodge in Longmont a shot. They completely replaced the rear diff in my 2010 SRT under warranty. The kicker is that my car is supercharged and they looked the other way for me. They're a smaller home town dealership. I had my windshield replaced (stress crack) at the GO dealership on Arapahoe Road last year. The service manager acted like he had to pay for it out of his own pocket and gave me a bunch of crap about the blower. The drive up to Longmont to replace the rear diff was worth it. Minimal BS from those people.