To install you need OpenIV, then just open vehicles.img and make sure you are on edit mode and then drag and drop the files in there.
Then open handling.dat and find blista and change it to this:

BLISTA 670.0 0.00 85 0.0 0.00 -0.23 1.0 5 0.170 1.0 175.0 0.21 0.660 0.45 34.0 1.33 1.06 14.2 0.12 0.4847 2.2 1.5 1.5 0.09 -0.13 -0.003 0.50 1.0 0.6 0.9 1.5 0.0 15000 440000 1 0

Enjoy.

Credits

Amistech Games- for making the car
GTA Mods Del Norte- for porting the car over to SA
CarCrasher730- for porting the car from SA to IV

Changelog:

0.1
Fixed the specmap textures and hinges,
Added dirt texture to car body.
0.2
Fixed door hinges again
Added a few tuning parts

0.3
Redone the model convertition
Fixed collisions
Removed unused texture
Backlights now have backcase
Added handling and changed the weight to match like in MSC