A motel-suggestion which might be helpful:
http://www.hotelformule1.com/formule1/index.html
Formule 1 motels are located almost everywhere throughout Europe (Except for Italy and The Netherlands) and are a cheap and ok way to spend the night! Usually a room will cost you some € 28,- and, depending on which country you are in, may be used by 2 or 3 persons, but since you'll be traveling with 4 people, you will need 2 rooms. The rooms don't have a shower or a toilet, these are located in the hallway, however, there is a sink in your room.
You might want to check http://themepark.nl/php/tporganizer/ for a detailed scheme of parks around the world, and especially in Europe. This little database is filled with experiences from Themepark.nl members and features some handy tips. The downside to it, is that it is entirely in Dutch, but if you really are interested in some of these details, please let me know, so I can translate for you!
A last piece of advise: Be sure to spend enough time in Mirabilandia! Katun is one of the greatest coasters I've ridden. Also be sure to check out their River Rapids ride. It's a realy nice cooldown on a hot day
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As for QUESTION 11:
We did a similar trip once, and what I can remember, is that we had to wait for almost an hour for the Gotthard Tunnel which connects Switserland to Italy. I'm not sure what the reason of this holdup was, but it realy slowed us down! (by the way, we were traveling in a minibus then too Be sure to have airconditioning in your vehicle! It can get pretty hot in Italy! (South Germany to ))
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It's such a pity you decided to skip Efteling park in the Netherlands. I know that you guys didn't think too much of it during ECO, but why not give it another try... After all, it's probably one of the world's oldest 'modern style' amusement-parks! I agree, that the park doesn't feature the worlds best coasters, in fact they're almost all Vekoma-rides, but I think the park is beautiful to stroll through and features a great fairytale-wood! But hey, it's all up to you guys!
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More and more tips fall into my head Here's another one:
Buy a Thrill pass at Walibi Belgium (former Six Flags Belgium). My experience is that when you order a pass, you can pick it up when you leave the park. This pass offers you free entry to the folowing parks:
Walibi Belgium
Walibi World
Movie Park Germany
Walibi Aquitaine
Walibi Lorraine
Walibi Rhone-Alpes
Bellewaerde Park
If I had to choose between Walibi Lorraine or another Walibi park, I would go for Walibi Lorraine. It has a funny wooden coaster, which has anti-rollback devices on the hills that should have provided airtime. In other words: It sucks as a coaster, but it's great fun riding it with friends!