I think we all like the new HD tank models (not sure if I'm allowed to link to them)
However, I've heard a lot of people saying the new models are "too shiny/clean", "not rusty/dirty" enough.
What if, as we play games in the vehicle, we unlock levels of "grime" which we can choose to apply or not (much like another game I could mention)
0-50 games - shiny shiny, it hurts my eyes
50-100 getting muddy and dusty now
100-200 mud + rust
It would be a nice "bonus" for veteran players playing the same vehicle over and over again and would add some variety