First off, the VW will always lose more than 10% in th first three years, but let me answer your question for you.
Ultimately, a used vehicle's resale value is based off of the price of the new vehicle, market demands and general reliability.
Here's a general example: Let's take Chrysler's 300 (remember it's not a C unless it has a Hemi). In March, a new 300 may sell for about $35,000, but when you factor all the incentives and common negotiations, you can buy the vehicle for $29,000. Now let's look at a Toyota Avalon. In March, a new Avalon may sell for the same $35,000, but after the smaller rebates and negotiations, you can get it for about $33,000. This creates a $4000 difference in value right off the bat. Now take the same cars in September, the next model year has come in so dealers are pressured to sell the remainder of the previous model year. Now the Avalon may sell for $31,000, but the 300 now sells for $25,000. At this point, there is now a $6000 difference.
I say this because now used dealers are looking at the KBB (which is judged off the reasons I listed above) and are showing the Avalon is still worth near its new price (since the new buyer won't save a ton of money) while the 300 has lost a great deal of money since the new ones are so cheap.
OK, so that makes pretty simple sense right? Now, when it comes to market condition, this also makes a huge impact in value. Let's take the 300 again. When they first came out, everyone thought they were as cool as can be, which kept the values high the first year or so. Over the winter/spring, when we were paying $4/gal, the Prius went though the same kind of price inflation.
Now, reliability. This is where Toyota and Honda really excel. The general public knows that these vehicles are more likely to be reliable, so they are more inclined to purchase on that is a bit older or has more miles on it, thus the vehicle holds its value.
American products are typically going to lose more value faster than foreign products because they usually have larger incentives and are not as reliable. Scion for one, never offers a nation-wide rebate, and therefore hold their value extremely well. Mini always has a high demand, so they hold thier value well too.
Just a bit of information, but I hope it helps.