The frame, suspension, engine/trans, electrical system, brakes, almost everything is different or not compatible with the G5 let alone the Goblin. I am concerned that you are worried about budget, but the reality of trying to modify, adapt and reengineer a Vibe will be far more expensive than selling off the Vibe and finding a Cobalt or G5. That is unless you have a really big budget and a fully equipped custom auto shop. Sorry to be frank about this, but just don't want to see someone new to the forum go into this project thinking one thing and spending far more money than needed to complete their car.