jack points?
 

I want to put my S5 up on jack stands. If I put my floor jack under the proper spot on the side, as defined in the owners manual, I have used up the spot, where do I then put the jack stand? Is there a spot under the car, in the center, perhaps a cross member, where I can lift the front or back of the car, then put the jack stands on the side "spots".

Not sure what S5 model you have but you may very well be fine using a spot on the pinch weld between the front and rear "proper spots" to lift the entire side of the car and place a jack stand under each of the "proper spots". Then repeat on the other side of the vehicle.

In any case, you are soley responsible for your (and your vehicle's) safety so be safe about it.

I usually use a flat spot on a suspension arm for the jack stands.

2020 answer to an old question
 

I know this post originated long ago. But, it is still relevant. If you search, ' Where to put a jack stand on an Audi A5', it reliably is at the top of the search. So, the question still gets asked. Here are two products I use. Both are fairly new, last couple of years on the first, and very recently released on the second. I prefer the second.

1) https://www.powerbuilt.com/collectio...ack-floor-jack + https://www.powerbuilt.com/collectio...ton-jackstands

2)https://www.powerbuilt.com/collectio...ckstand-in-one

Both are well built. The all-in-one, I have to drive up onto 2x6 pieces laid flat to get it under my A5. But this is fine.