I have a solution to the hood dilema without needing to mod anything. This may even be the way Hasbro intended it since it seems to work so well (though the instructions are crummy anyway).

 

On the back of the cab (the flat peice with the exhaust pipes) you should look at the bottom of the peice and there is a groove. When in robot mode, this grooved section is near the shoulders. Now, when moving the hood into position in robot mode, slip the cab's folded rear doors into this groove. Done.

 

Took pictures last night so people could see what this looks like.

^^^ Wow. that door hinge trick WORKs WELL. awesome. I already altered the springs -- and can say that THAT mod was worthy as well -- made the shoulders less er,... springy & floppy.