Thank you doctormaxart, Rick and ekuth
as for your questions, Rick:
first of all check your inbox
on the other matter, the trailer was planed as a separate model, coming after this one, and they even did a test build but eventually dropped the idea, i don't know why.Maybe because it was too complicated, maybe because of low sells of this model..
about tires - nothing special, i build it by instructions, but after i finished gluing the tires a sanded the edges, to get them more round and realistic, i cut the picture of tire perimeter by lines, to imitate the real ditches and painted the whole tire in black.