Makes all cars faster, better, not stronger though.
Flooring the gas pedal feels fast, responsive and you can now drift with ease :)
(see end for change log)

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.

v0.1
All cars have increased engine torque and handle better for their corresponding speeds. Top speed stays the same across all cars.
v0.2
Bullet:
Acceleration reduced slightly.
Steering angle increased slightly.
Car weight matched to its real life counter part, the Ford GT.

v0.3
Entity XF:
It's a supercar now.
Traction and Handling are improved.
Top speed is the actual real life top speed of the Koenigsegg Agera, 274 MPH.