I know just before you asscend the lift hill you hear:
"For your safety, remain seated with your seat belts fastened, keeping your hands, arms, feet, and legs inside the bobsled. And be sure to watch your children. Thank you"
But that is before the ride, and I am not sure whos voice it is.
After the ride you hear the extremely fameous
"Remain seated please; Permanecer sentados por favor"
Which is definitly Wagner
[ame="http://www.youtube.com/watch?v=UXu5bXdVvuI"]This[/ame] Youtube video shows that announcement at about 1:15.
(After reading the FAQ, I'm pretty sure that that link is ok to post but if not, I'm sorry)