According to most Americans Tirerack.com is the place to go for tires when you are stationed overseas. Some say that the price of tires in Germany and The Netherlands are just way to high to pay. That is opinion, but we here at GK must be open minded and so I am putting this website out there for those that would like to try them out.
I drive a Subaru Outback Limited 2.5 with 17 inch rims. My tires are big and costly. I went to the site to find that they boasted a 107 USD price along with a 55 dollar per tire shipping fee. That seemed reasonable to me for my Hankook Optimo tires. I check with Schinnen and their price was 235 USD per tire. This price included no mounting. So tirerack seemed legit. So this is 324 for the two tires I needed plus I had to pay someone to mount them. This would be minimal at about 20 dollars. It can take between 1-4 weeks for delivery.
Then I went to Van Son, my go to place in The Netherlands (see blog on this site). They are charging me 112 euros per tire and that is for mounting and balancing. Then we must add the 19% sales tax because I can not get my VAT back because I live in Germany. This comes to about 349 dollars for both tires. Best part though, I get them in two days MAX!
See both sites and compare to get your best results. This is bias on only one type of car, but just to keep your options open there are the two place I know about!
Site is very easy to use: http://www.tirerack.com/
Here At Gk 
Since you live in Germany, you might want to cost them out there. Most everything is cheaper that side of the border, anyway, and you’d get your VAT back.
bookmarked!!, Ӏ like yοur website!