Hi I just picked up a 2008 2 door 5 speed and did a few hundred kilometer shake down trip with it. I've found when shifting out of first gear to second it will kind of clunk like the engine moves a bit due to the torque of first gear. Most of the time all other shifts seems smooth and fine. I had a look under the car for possibly engine mounts worn out but really didn't fine any blown out. Are their common mounts that go bad causing problems like this? .I don't fine sometimes the shift is fine if I shift at higher rpms.

 

Mine is doing the same thing and I bought a replacement one got it all on it worked until I got right down the street and realized I forgot my wallet and when I turn around it had came out of the transmission but before that happened the noise was gone which sounds like what you are dealing with let me know if and where you find a part the compressed length of the oem is 41.7 from gm themselves and all I can find is 37.4