Okay it most likely wasn't templated to UV channel #2. I'm not sure how experienced you are with modding so I'll explain.
When you UV map a object you can select what channel to map it too. Here is the window that comes up with the option shown
I think the model wasn't mapped to UV channel #2 but you are telling the material to look for the mapping on #2 but it doesn't exist giving you the black.
No you can't have two sets of extras for different parts of the car. But you can have extra_1 on one door and extra_4 on another but they can not longer be used anywhere else on the car because they would move when the door opens also.
Another London Underground emergency response vehicle! This vehicle is used by the duty manager to respond to urgent calls and is based at Camden, North London!
Video showcase
http://www.youtube.com/watch?v=VSJgG51lBw8
A skin for BPM's LFB fire truck changing it too a London underground emergency response unit truck. The skin is based of the new trucks after the department got 10 new trucks after the great work they completed during the 7/7 bombings in London. They proved to everyone that terrible day how important they are in the safety of millions each day that use London's underground!
Video Showcase
http://www.youtube.com/watch?v=cPzTMHDuh6E
You can save objects under the objects menu there is something called "save to objects.ini" you can then give this out to anyone they put it in the main directory and then they press "load from objects.ini".
Description:
Ever wanted more choice when it came to London ambulance service vehicles? Well now you have two new Rapid response vehicles and one brand new ambulance with accurate interior and patient lift that works! All skins were made by me from BritishPoliceMods cars I've been given full permission from him to release these cars with my LAS skins.
Features:
High quality skins
Hex affect in batternburg patterns
Accurate reputation of LAS RRVs and Ambulances
Handling and IDE lines for two out of three of the cars.
Showcase Video:
http://www.youtube.com/watch?v=x4x1n-3jKjU