We have a 2008 Pontiac G6 GT hard top convertible that we bought new in 2008. It has the 3.9 L engne. We have loved the car. Recently the top stuck a couple times when we tried to lower it. It went straight up, the trunk opened but the top would not continue to go into the trunk. It would come back up and lock down and show top move complete. We took it to local GM dealer. They said they tried it about ten times and it only stuck once. They could not find any thing wrong. So they lubricated all the moving parts. It then worked three or four times and then the last 3 times we tried it stuck. Can any one give any info or pointers as to what is wrong?