Well, i spent some time fixing robban's Sierra, and well here it is:

RS Cosworth:

RS 500:

2.0 GLS:

It comes with RS500, RS Cosworth and 2.0 GLS

Fixes:
Cars now come with all their parts at catalog
RS Cosworth had some parts mixing
Cammera Fixes, Java Fixes, Parts names, More.

I Dunno who modeled this car, I just know Robban Converted it, and i Fixed it

Upload anywhere, just make sure to put ROBBAN as the Author.