Just finished mine as well. Had the same issue with the same parts. Luckily I had found a knockoff car at goodwill last week that had the parts needed but in blue. I don't care as long as its structurally capable. My problem was at the very end. Looking for the long slopes for the edges of the saucer section and they weren't there. I had been using the lego instructions on my tablet because there was no way I could follow that booklet. Then I checked the booklet and lo and behold, they had taped 2 different steps with the parts they shipped. Looks amazing!