Beware of the old Landspeeder...

My main problem with minatures is that I want to do everything at once.
Yesterday evening I started to work on a Landspeeder model that I bought a little while ago. This is the most troublesome kit I have built so far in the Warhammer range.
I haven't built much transports before, but I have quite a lot of experience from building 1/35 scale models. Plenty of hulls being assembled, and the difficulty level varying from very easy to quite hard. So with this in mind I cut out all the pieces for my Landspeeder and got to work thinking that this should be a quite pleasant build. Boy, was I wrong!
After painting up some of the interior details, I started to assemble the Landspeeder according to the instuctions provided in the pack. It went ok until the top piece was to be glued on. Nothing would fit at all! The middle section was too long, and after assembling the controls the front did not fit at all! Then when I finally got the front to look almost decent, the middle support section was suddenly too long and would not fit at all.
Obviously I must have done something wrong with the assembly even though I followed the instructions provided, so now I am sitting with a hobby knife cutting and filing small pieces off the fuselage to get the top piece on to the speeder. When that is done I think the speeder will need some greenstuff to cover up a few minor glitches in the fuselage that appears in some places.
It might not be the prettiest Landspeeder in the 2nd Ultramarines, but I won't quit working on it before it looks fairly decent. Then I will buy another one next time I am at my local GW store and see if I get the same problems with that model...