I recently purchased a used 2001 A6 Avant with 6K on the odo. This is the perfect family car and touring wagon for any avid skier, golfer or any weekend family activities.  Three weeks after I purchased the A6, I loaded it with three of my buddies (all 200+ lbs each) for a weekend ski trip to Killington, VT.  Between the four of us, we had luggage for three days, 3 pairs of skis (in the Thule ski rack) and 2 snowboards in the trunk area.  I was surprised to see that the ski sack in the back seat was large/wide enough to accommodate 2 snowboards.  The A6 was more than enough space for the four of us and the front/rear heated seats was an added bonus for our aching backs.  Now for the product review.  With my weekend lifestyle and having our first kid on the way, I decided to invest in the WeatherTech Cargo Liner.  There was no way that I was going to let muddy ski boots and other items to ruin the trunk area.  I looked at the Audi OEM Foam version and was not impressed.  It is made of a low grade foam that is easily prone to ripping.  The WeatherTech version is designed with a 3" lip which helps to contain spills from leaky groceries or wet snow boots; perfect for hauling gardening supplies, fishing gear, construction materials, golf clubs, or carrying the family pet. Cleanup is quick and easy with a damp rag is all you need.  Here's how I would compare the two:  Audi OEM is Foam ($50) and the WeatherTech is a durflexible plastic ($80).  Both are customized to fit the cargo area for the Avant and Sedan.  The only thing that I didn't like about the WeatherTech was how it worked with the cargo net.  Because the WeatherTech has such a high lip, it makes it difficult to hook and rehook the cargo net into those chrome eye holes.  Regardless of this, the WeatherTech is the best way to go.  The price difference is worth it!!  You can purchase either version online at www.clairparts.com.  I live in the Boston area so I picked it up at the parts counter.  Enjoy.