It might be complicated but the results are very good, and cool, and you are going to end up with a highly original and creative model. Please keep it going.
I agree with Bill, if I don't see (or lose one) something I like, I wait around. Besides, I am not a collector, I am a builder and as such I have plenty of WIPs on the bench.
I sand mine, and it's always a lot of work, but it helps relax me. I do agree with J on making the tires out of styrene too, and when you look at the work military builders have been doing to make their tires look ultra realistic you realize they are on to something.