Instructions
You NEED OpenIV 2.6.
1. Open OpenIV
2. Go to update > update.rpf > common > data
3. Enable edit mode
4. Copy handling.meta that I provided and put it here.

Then get into the Adder and feel the resoluts :)
- it changes the steer of the car, you can steer much faster
- it makes the Adder heavy, check all other cars out of way

HAVE FUN!!