Illegal Lego builds

I'm fascinated by this PDF, by Bram Lambrecht, describing the difference (with examples) between legal and illegal Lego builds. [via MeFi]

In it, Lambrecht describes 'the model that forever changed LEGO,' an Audi TT that was difficult to put together, required the user to deform components for them to fit, and came with no instructions.
As a direct result of this set, all models now produced by the LEGO Group must go through the Design Department. This ensures that nothing gets released without first being approved by a Model Committee. Sometimes lasting up to 2 or 3 days, this review allows representatives from building instructions, senior designers, engineers and the designer sit down together and build the model. The goal is to maintain an ‘only the best is good enough’ approach to our design process. A final heat test then highlights further weaknesses that must be changed before the set can be launched out onto the market.