This ENB will improve reflections for vehicles and vehicle glass (Works for every patch and also with EFLC). 
For patch 4 (1.0.4.0) and below it also improves reflections for blood and reflections for any kind of rainy weather, vegetation colors/brightness, night lights and vehicle lights.
It doesn't add other typical ENB shaders/effects like bloom, adaptation, lens flares, AO, clouds and other things. Just the upper mentioned things.
You also have to expect a little performance lost of 2-4FPS.

Installation:
Put the files from the "Files" folder into your GTA IV main folder.