I had all of these issues and then some with my 2011 Regal RL6. Mostly engine and brake problems. Things got so bad to the point where GM finally replaced my vehicle with a 2013 Regal Turbo III, and gave me $8825 cash back on top of replacing the vehicle. It was a nightmare, but here is the shocking news.....
The Buick dealer, specifically the general manager, where I picked up my new car, stated that he had four 2011 Regals dropped off at their dealership as lemon buybacks in ONE MONTH! I was his 5th, and this has all started to happen recently, not over a long period of time. He told me they were all the 2011 Rüsselsheim built Regals, and the Rüsselsheim models only....none of the Oshawa models, and none of them 2012 or 2013. Even the finance manager at this same dealership turned in his 2011 Regal (Russelsheim) as a lemon. The general manager and finance manager stated that some of the cars had issues from the beginning, and mine was certainly one of them, with problems beginning at 4400 miles, but the bulk of problems were happening between 18,000 and 30,000 miles, and people have been coming in droves to replace their problematic 2011s, even if just for a trade-in/trade-up rather than a lemon buyback.
This is a bit alarming. It would almost seem to me that the 2011s built in Rüsselsheim have some sort of "shelf life" issue going on--good for about 2 years or 30,000 miles. I wonder how much more of this we're going to see. It's really a shame because it's such a beautiful car, and Regals, to me (even the base models), aren't inexpensive.
If you own a 2011 built in Rüsselsheim, or any other model having issues, my advice would be to contact GM right away and have them start a buyback. Granted, they were not easy to work with, and I did have to get an attorney (at no cost to me) to help me negotiate the deal I got, but we should never be tolerant or complacent of all these problems given the top dollar each of us has paid for our Regals. So far, other than the Intellilink system driving me nuts, my 2013 is great and "seems" to have all of the bugs worked out right from the get go. Time will tell, but it looks like the 2011 Rüsselsheim is just infected with glitches and bugs. :-/