Manik: Washes is how I get the majority of my weathering done now as far as giving your 223 a dusty look I would try a couple things myself i:e very thinned white and desert yellow paint on the surfaces,, Remember as I am sure you know dust gets every where,, even spots you didn't think it could. I have been in the military for 19 years and have seen the dust kicked up by vehicles and let me tell you, everything gets dusty so I wouldn't worry if you get the dusty look in places you wouldn't expect dust.
T3488g I am doing a M8 armoured car,, me personally I wouldn't see a problem with you doing a 8 rad. Just my opinion,, but then again I am not running the build so its not my decision.
Progress report. Will have pics up and then emailed of my finished 222. Aftermuch panic I found my instructions for my M8 and will begin the building process tonight. Hope all is well with the rest of your builds. From what I can see in some of the Pics I would say yes.