My friend has a 1997 GST. It was having some vibration problems. I check the balance shaft and the tensioner was kind of loose. I fix that and the vibration went away. Now, he is telling me that after 65mph, the car start to vibrate. Something wierd is that there is almost no space between the bottom of the engine/transmission and the black frame support that goes from the bottom radiator support to the back of the engine maybe, maybe .25 inch separation. Well, I changed the broken side engine and front engine mounts, but still the same. The other two are in good condition and there still no space between the engine/transmission and the support.