No, not yet.

My dad tried to earlier this year, though he went about it the wrong way. Since you can't actually asphyxiate by running the car in the garage scheme, it didn't work and someone got to him in time. I actually didn't know that, and found out after it happened that all car companies install catalytic converters in mufflers to stop almost all the toxic CO2 from coming out the tailpipe. So anyone that wants to off themself, don't sit in the garage with the car running...you're wasting your time.