I script a couple rides and SCO objects and I'll like to post a few pointers for modelers who aren't familiar with how NL2 connects with these objects through scripting. First and foremost, the ride HAS be broken down into whatever components are going to be moving. If the object has no named sub-groups, components, or hierarchy of any sort, the ride will be impossible to animate. Secondly, the groups within the model have to be named uniquely, meaning that duplicate named groups are a no-no, how will the code know which one to reference? Next make sure group axis are somewhat relative to the axis that the component will be moving on, it's a lot easier if these are setup in the model rather than corrected by code.
I'll use this Booster Ride as reference: http://en.wikipedia.org/wiki/Booster_(Fabbri_ride)#/media/File:Hydro_Max.JPG
Look at how many axis that the ride will be rotating on, there are 7 (The main rotation, 2 gondolas, 4 restaint sets). You will have to break the ride down into these 7 components, and have them contained within another. Arm which contains the two gondolas, each which contain the two restraint sets. Let's name these now within a 3D editing program; they all have to be named differently in order of NL2 to retrieve the right piece. Here's what I would name them: arm_Main, car_0, car_1, restraintSet_0, restraintSet_1, restraintSet_2, restraintSet_3. This is a very good example of naming objects, a descriptive name, no spacing, duplicate objects, like the cars and restraints, begin with Zero, not one. I understand in SketchUp, components are easier to work with (Yay!), but cannot be named differently(Boo!), you will have to use the "Make Unique" action in order to name them differently.
Now for the sub component axis, move the group axis exactly to where the object will pivot. For Booster, you'd want to place the main arm's axis in the center of the arm; the car axis between the seats; and the restraint axis where the restraint rotates to open, near the headrest. Failing to so will cause the ride to rotate around a completely different axis. I understand in some cases this is a bit unavoidable. Rides who's axis are not on X, Y, or Z axis will have a slight issue here. Booster only rotates on X or Z axis depending on what direction the model is facing. Wind Seeker and Enterprise for example have multiple gondolas, the do not rotate on X, Y or Z, they rotate somewhere in between. I am familiar with one way of correcting this, as a modeler, point all of your sub groups so that their rotational axis in on X, Y or Z axis. Look at my Sky Whirl or Projection's Wind Seeker, you'll see the in the editor the model are propped up in an odd way, like in Wind Seeker, all of the cars are pointing in one direction, it makes coding easier as all us coder's have to do is rotate them once to correct them, instead of using another method to rotate these groups along a non-XYZ axis.
Lastly, make sure your models are in their resting position. The Parasail model that Talon was so kind enough to post, looks amazing, but it would be pretty difficult to animate, as it's in a mid-cycle position and it's harder to correct that into a resting position and then animate though coding, there's a bit more that can go wrong when calculating angles for the ride as opposed to having the model start in a resting position.
Also with what is being said about using SketchUp Warehouse objects, please give credit to who's object you are using, or even better, contact the creator to get permission to use their work so they are aware that it is being used. I personally do not feel comfortable editing or animating rides that were found on the internet, as most times they aren't rigged correctly, and posting the work leads to the assumption that the model is ours, which wouldn't be true.
I hope this helps you modelers out there. I know it's a lot to read, and a bit confusing. Feel free to ask questions on the thread so everyone can learn or PM me if you're having trouble rigging your models correctly, and I can inspect them personally.