When I first heard about these lines I read that they had engines that could turn into weapons. I was a little disappointed that they were fairly basic. Imagine if the engineering and complexity of these lines was taken further? A large, highly detailed engine that clicks into the inside would look great. It'd be brilliant also if it could turn into a massive, detailed BFG or actually form into the arms.
Other things like this might be:
Spare tires in the boot (with wheel trims) that can transform into shields or weapons.
The robot limbs themselves having weapons containers (like in Robocop)
Imagine if you could turn the robot limbs "inside out" so their appearance was changed (ie more aggressive or armoured).
How would you feel about something like this? Good? bad?