I was daydreaming of a similar idea, but it sounds like you have a lot more going for you than I could ever hope. It sounds like a great idea. I'd start by putting together your ideas and posting them in more detail here and setting up a slick website. I suppose their are all kinds of threads of red tape you'd have to negotiate working in a foreign country, but I bet John Lance the Winter Tire Guy might be able to point you in the right direction. Let me know when you're hiring your staff. My German sucks but I could do your airport pickups and transport to the Welt and definitely point out the cheapest ways to get around in Bavaria. Been doing it for 4 decades and have been able to do so because my wife and I are so freakin' cheap.
Home in the Poconos, heart in the Alps
2012 BMW 128i Convertible (red)
2013 MINI Cooper Coupe (red)
2014 Ford Fusion (grey)