You're paint job actually wasn't bad, and it would have looked just fine with some advanced weathering techniques over the green. I have to admit that I'm a fan of white military vehicles and I have a soft spot for whitewash. One quick thought, the tracks wouldn't retain the whitewash both because their rusted and dirty surface provides a poor surface for paint adhesion and because they are in constant contact with the ground and tires where friction rubs it off. The same applies with the tires both because of friction and because rubber just doesn't accept paint well, but the whitewash can remain on the sidewalls for a short time. Just remember rust and rubber are not friendly to paint The rest of your whitewash is really good, it's applied over everything indiscriminately which is pretty much what they did. A lot of modelers leave small details unwashed to provide contrast for visual interest, but it's less accurate when they do that.