Buyer's Regret 
2017 Toyota Sienna Minivan Limited Premium 7-Passenger 4dr Minivan (3.5L 6cyl 8A)
Big Transmission Problem - STAY AWAY (UNSAFE)
 I bought this car brand new after test driving a couple of times.  As the computer learned the driving habits, it's supposed to adjust (fine tune) the transmission over a period of time.  Well, this fine-tuning thing didn't improve the drive.  I took the car to the dealer 3 times.  The dealer said they couldn't find anything wrong during the first two sessions.  They offered to reset the computer.  Finally, the 3rd session, the service manager finally admitted that this is a know problem, but he couldn't do anything about it.  I tested drive another brand new Sienna and it's pretty bad as well.  I'm an engineer, and crying and regretting buying this car.  FRIENDS DON'T LET FRIENDS BUY A FLAWED SIENNA.  PLEASE STAY AWAY.  I REGRET NOT BUYING ANOTHER HONDA ODYSSEY.  Here are my problems:1.	This occurred five times - When driving on the street at 40-45 mph and slowing down to a stop on a red light at the intersection, the car jerks (stutters like the transmission or drive train gears can’t transition) significant enough for my wife on the front passenger seat to ask what’s wrong with the car.  The car had 60 miles on the odometer when the first occurrence happened.  The car now has 275 miles on the odometer.2.	I do not feel any acceleration for a second or so then it kicked in with a big gear kick, especially when:a.	 I go over speed bumps at a slow speed, and press on the throttle after going over the bump.b.	 I lift off the throttle approaching a corner, and pressing on the throttle half way through the corner. Feels like the gear slipped (engine whines, but no acceleration) then exerted a big gear kick.  3.	I noticed that while I turn left on curve road (in the neighborhood) around 15-20 mph, the gear stutters a little bit, enough to feel like the wheel hits loose gravels.4.	In general, it appears the engine whines a lot when accelerating from stop.  It feels like there isn’t much torque.5.	Overall the driving experience for the past couple of weeks has been dreadful.  Spending a lot of hard earned money for a car that constantly reminds me of problems is not a happy state of mind.I tried my brother-in-law’s 2014 Sienna, and it does not exhibit any of the problems above.