Anyone recently choose to sell back?

If so, how long does it take from the time you pull the trigger to the time you drive onto the dealer lot? Any chance I could decide today and have it done within the next two weeks?

You should check out the Dieselgate section. Lots of information there including a spreadsheet with timelines. It's usually taking anywhere from 30 - 90 days to complete, so no, you won't get it done in two weeks. Closing thread - feel free to continue discussion in the Dieselgate section.