Update:

The warranty company sent out an inspector last Friday for the final time. Although the problem didn't replicate, another problem arose. He said he noticed there a soft 2-3 shift with sight RPM flare. This had never happened to me before, but started while it was in the shop. He said the shift was out of spec, so that was enough evidence for them to see there was a problem inside somewhere. They authorized a tear-down to find the problem. While tearing it down, they said they found--1) broken 2-3 band (whatever that means, not quite sure)--2) The pump was scored with grooves in it--and 3) "Converter debris" in the fluid. If anyone would like to shed light on what that means, feel free...I'm kind of curious!!! Not really sure if any of this was what was causing my original concern or not as they just tore down to find out what was causing the soft 2-3 shift. They sent an estimate over to my warranty company yesterday to repair the issues they found, and I talked to their adjuster this afternoon. She said she has ordered a replacement transmission as it is more cost effective for them to just replace rather than repair. Still has me wondering what was causing the issue with taking off when cold sometimes. I see this is a common issue and was hoping to figure it out so I could pass on what I knew to everyone else. The car has been in the shop for almost 8 weeks now!!! I only have 20 miles left before the warranty expires!!! Luckily, the dealership provides a loaner vehicle while yours in in their shop. I'm definitely missing my GXP!!! Transmission should be in by middle of next week!!!