Well I had a multi paragraph detailed explanation all typed up for why you'd be wasting your time with the texturized surface, but Ecomodder had a glitch and ate what took me an hour to prepare. I guess I've gotten lazy and am not essentially writing my posts in Word and then copying them back into here. Shame on me I suppose.
So I'm a little upset right now and don't really feel like typing it all in again.
Research what you want to do and you'll see it does not work for cars.
The reason is your car is not a shark in the water. It is a brick trying to push its way through air. Laminar flow disruption helps the shark because laminar flow drag or skin drag is a large component of the total drag on a object in water.
Skin drag is a very minor and essentially insignificant drag component on a car moving through air compared with pressure drag. If you want to improve your cars aerodynamic performance you need to change the way the air flows around it by changing the shape of the car and optimizing the pressure differentials.
Here is a picture of shark skin which I think is amazing in its complexity. It is one of my favorite images of all time, the shapes are just spectacular. It is the result of billions of years of evolution. Trying to reverse engineer this would be a lifetimes work in getting to understand all the details involved in it. The image was created by Eye Of Science.