Well, I've got a plan in theory. Seems like it all should fit, just by eyeballing it.

Gonna chop the piledrivers in half and glue in bionicle ball joints. Fit the ball socket onto the Jeep arm's pivot point and it should fold up without having to go into the shaft. I just need to chop the inside of his arm, where the back seat would be.

Might need a stop tab in the shaft, but should hang down to about there when I'm done.
Thinking about doing something with a flashing led, but I should stick to dealing with the arms first. The chest area is the other question mark.

Thanks for the offer Clay. I actually could use another skids for another project, but I should try and cut back my transformers spending (at least untill I clear up my backlog some). If its still there in the new year...