Last week, visitors to Disney's California Adventure got a chance to view the new Muppet Mobile Labs, a two-wheeled vehicle on which ride muppets Dr. Bunsen Honeydew and Beaker. The muppets performed a brief show during which they interacted with guest and conducted various experiments (for example, seeing which of a variety of dangerous contraptions Beaker could escape from before they exploded).
There were a number of technical problems that need to be worked out before this becomes a permanent addition to DCA. Apparently, the two (very short) puppeteers who work within the vehicle had a difficult time operating the puppets, responding to guests, and driving while simultaneously keeping their balance. Said one puppeteer, "Sure, a two-wheeled vehicle looks all cool and scientific, but it's a pain in the ass. If one of us so much as coughs, it falls over, and they take the repair costs out of our pay."
Look for Muppet Mobile Labs to appear on DCA's regular schedule sometime later this year (possibly with the addition of a third wheel).