Bro! Congrats once again!
Here's my advice:
So, routes look good, biggest thing, keeping driving less than 500 miles/day is very good idea. It's exhausting driving so much in one day in foreign countries, and then you'll have your wife with you on top of that, trust me it is stressful. No one really talks about that.
I'd highly recommend moving your delivery day to day 3 of your trip. Spending 2 solid nights adjusting to the time zone will pay massive dividends later for your body and your health, and energy levels for the rest of your trip.
Plan on getting a little lost. Factor that into each day. There was one time I missed an exit on the Italian Autostrada and the next exit was over 20 miles away. That ate up time, money and miles on the car.
Gas is not cheap over there. Plan for that.
Try to get a full 10 hours of rest each night. It'll give you good energy for the days driving ahead and keep your immune system high. That's a rule we have as airline pilots, 10 hours "uninterrupted rest" minimum.
Don't forget about your wife. Europe is a very romantic place and a great ED can lead to happy memories in your future.
Study up on driving laws and what you'll need. You'll need stickers and have to pay certain taxes and tolls driving through Austria, Italy, and Switzerland.
If you can coordinate, I'd highly recommend caravanning with other ED'ers if possible. Especially ones who have done it before.
Try to hit the Autobahn as least once in an unrestricted section. It's legendary!
Drink lots of beer over there. It's the best!
When you get to the Ring. Trust me. Do the first lap by yourself in the car. This way you can learn it a bit and also enjoy your time with the car. It's a bonding experience between you and the car the first time you drive it on the Ring. After that, have your wife travel with you on every subsequent lap if she wants to.
Most of the roads and highways over there are 10 times better than over here in the USA. If you do get a flat though, know immediately who to call and how to handle it.
In September, there is rain in Europe. Plan for that. You might want to bring a small umbrella or rain gear.
That's all I can think of for now. I'll add more later if I can remember more stuff.
