I'm looking to jack up my 02' A6 3.0 Quattro to do an oil change. Is it okay to lay a piece of wood between my jack and the rubber coating on the underside? What's the rubber coating protecting anyways?

Just so it's not mentioned, I know the pinch weld is where Audi intended the car to be jacked up from but I'm not using that point since my jacks can't lift there w/out damaging it.

Thanks,

 

Make sure the wood if beefy enough to not simply crack when it takes on the entire load of the car and the teeth of the jack dig into the wood. I've used the wood / jack combo on my M6 before because it's too low to get jack stands under it even when the jack is fully extended.

Also, use jackstands after you've got it at the right height. I know it may seem obvious, but you can never assume when dealing with safety.

 

If you are using a jack, then there are other jack support points other than the pinch weld points that you are referring to. The pinch weld point is for the tire jack, aka widow maker. The proper point for a floor jack is below the sub frame. You will notice a bump.

Here is a similar reference picture. Once again, you will notice a bump under the subframe.