@jamesster: Wow, you really know your bricks! Pretty interesting to see that some of these bricks were never released in those colors. I don't really remember, but I think we may have received some of those models. We had no idea at the time these were using rare pieces though! I guess that would make them worth quite a bit to a collector these days.
@JimBobJeffers: These models were made at the time while I was working on a different game. I would re-join the team later, by when the characters and most of the vehicle designs had been finalized. I'm pretty sure our team intended to have original characters only for the game, and not use any existing Lego characters.
The jungle boss, Snake, was based on Colonel Kurtz from Apocolypse Now - his face paint is inspired by Kurtz's face paint pattern.
Here is the next batch of photos (dated 29-9-1999).
Another failed attempt at the muscle car, by the looks of it.
This is easily my favorite design of the X-car. Probably didn't pass the safety test.
(Yes, still more to come!)