1. Q1: If the car has the '"usual" little circular plug, it should work. You might want to drop griffin an email to make sure.
Q2: I believe it will work for the 3g and mini. It looks like all you need to do is plug in your firewire to dock connecter plug and you should be good. It also says that it works with all ipods but doesn't explicitly talk about the mini. You might also want to ask about this through email.
makes one that will definitely work with both ipods and its cheaper to boot.
Also, Monster Cables
makes a car charger and fm transmitter in one. Will work with both ipods but is more expensive. It also doesn't have the ability to play on anything but a car radio like the itrip and isnt as small. I would stay away from this because the itrip also has many more stations than this.
2. Q1: You could use an itrip2 for both the 3g and mini. It will look pretty stupid and get in the way on the mini because it will hang off the edge. You do have an alternative though. The Griffin Roadtrip
Will work for both your ipods, be a dock and car charger. It might be a good deal the itrip could get in the way and a charger could be a hassle and this makes them all in one smaller package.
Q2: I don't think there are any problems here. You may want to email griffin about it if you are really paranoid.
My suggestion is the roadtrip. You will get all your needs satisfied with this. No need to get things from different websites because that can be a hassle. It's what you want in one small package. It has more radio stations than the monster iCarPlay. (I'm sorry for my jumbled post, but I am not an expert and have not yet dealt with any of these products, although I want to help people get solutions for their problems)
Well on to cases. Two stick out to me. Tunewear Icewear
is clear and probably almost exactly what you want. I think it isn't fully closed like the iskin is but there is the tiny chance of your mini falling out. Also, I don't think there is any screen protection. My suggestion would be the iskin mini.
It has complete protection and a good screen protector. I think the arctic is somewhat clear, but I'm not sure. One thing the mini won't work in the roadtrip with an iskin on. I'm sure other people will also have other case ideas.
Enjoy my nice long post.