Bloody nice job m8s,btw what kits do you buy that have the swastika and the engine parts? oh and i have a model of a Tiger too but it's not painted good =(
I find pastel chalks work well,once the kit is finished,take your chalk,use a bit of sandpaper to create a small pile of chalk dust,then apply with a dry brush to the areas you want to weather,brown,grey and black all work well and look subtle.
Used pastel chalk to create weathering here.
This one was finished probably 3 months ago now (damn time flys) I will try to get some better pics tommorow when I find the good camara instead of the video recorder thingy