Cross-posted from Cruzetalk.
When accelerating into traffic and running the motor up to 3500 or above, the engine takes a long, long time to wind down and the shift to 2nd can be very jerky or there can be a lot of clutch slip because the rpm's are so high for 5 seconds or so. Something is making the engine lose rpm's very slowly, even with your foot completely off the gas.
IMO it's an engine management issue. To keep NOX emissions down, they use the engine management to keep the rpm's from falling quickly between shifts. If you accelerate to 3500 or so in first and just shift to neutral and get completely off the gas, you will see how long it takes the motor to fall to 2200 or so, which is the engagement point for 2nd if you want a smooth shift.
This is nutty. This is not an automatic, this is a manual car and the rpms need to fall quickly enough to be able to upshift without waiting for 5 seconds between gears or burning the clutch up, or making the car buck...