Saw that several people posted questions/concerns regarding seatbelts on several Disney rides (Dinosaur, Test Track, etc). I have a GREAT tip I learned from this thread and has worked for me ever since. It goes like this:
Step 1 - Get on ride and remain standing above the seat you will be sitting in.
Step 2 - Reach down and pull the seatbelt all the way up as far as you can while still standing or half sitting. You will be really suprised how far that baby can go.
Step 3 - Sit down kinda sideways, sort of on one butt cheek, turned towards where you need to click the seat belt in so you can see it and your, uh, girth isn't covering it up.
Step 4 - Click your seatbelt into place then scootch around into proper position and your belt will snug down on you like it is supposed to.
The first time or two you try this you will feel uncoordinated (at least I did). But let me tell you I used to get really stressed trying to get the seatbelts fastened - I carry my weight in my tummy, hips and butt and I do a good job of hiding the seatbelt with my ample self. Now that I know this trick these rides are SO much less stressful for me and this trick also kind of works on airplanes too! Hope I didn't offend anyone with any of my descriptive words!