There are both cg and non-cg shader files for this car that you can use as required. They are _cg shader car.shd and 
_non cg shader car,shd files located in the shader files folder.

To use them just COPY the one desired to the car folder, delete the car.shd file and rename the copied file car.shd.

I was unable to contact the creator of this great car so there is no permission to do the changes that I did which is one 
of the problems with old outdated cars, the inability to get permission to update some really great work!

Enjoy this fun and amazing car!

Boomer541