I read in one of the other threads that it's pretty much "while-you-wait".

Took mine in today to get my steering wheel replaced under warranty, also had my headlights adjusted, and the recall done. They gave me a rental, and wound up calling me to come pick it up about 2 hours after I dropped it off.

Unfortunately, they said they couldn't find anything about flashing the ECU.

The listed repair time according to the service manager at my dealer is .2 hours. I would expect you could schedule an appointment and be in and out in under 20 minutes. As previously mentioned, the repair was done on my car in the time it took me to fill out the financial paperwork.