Hey Mike, try to use Stuffit Expander to unpack the thing on Mac instead of UnrarX, which destroys the package by unpacking for unknown reasons.

As for the Zombie mode: Well, I don't really want it to be too complicated, considering pickups and pause-menu tuning. It needs to be one "flow". Like in the Zone mode: If I hit pause and continue later on I most likely loose because I am out of the flow for that session.
No matter how many Zombie ships we use, when Carlos appear, what weapons are used etc. there is one key thing that I didn't figure out yet: You gotta destroy the Zombies using the Cannon, right? And the Zombies ram you. What I don't want is to take away the speed of the mode. So you gotta have to move forward constantly, at least if you are racing on a circuit rather than Sao Paulo. And for a Cannon to be effective, the Zombies need to be infront of you. So I am not really sure how we can solve this problem...