So it took me a little time to figure out what I would do for TC7. I'm still not sure, but at least I have a concept.
Presenting the Boom-dozer
My tc7 work in progress by Russell Murphy, on Flickr
The basic concept is that the base stays the same, and the top transforms in some way to become a tank. Maybe the bulldozer arms could become some sort of armor. Who knows. Hopefully I'll figure it out.
I've used the subtractor from Sariel's excellent unofficial lego technic builder guide (http://sariel.pl/201...-available-now/) as a base. My 42048 bulldozer and crawler have provided donor parts. Not sure which functions will be automated, except for propulsion.
I think at this stage I'll be an enforcer, but depends on how far my white parts extend.
I'll update as I get further.