A fully-produced 15-minute episode of "Bill Nye the Science Guy" courtesy of Chrysler Corporation, who distributed the video to schools in 1997 as part of a campaign to promote airbag/seatbelt safety for kids. With all the wacky stylistic bells and whistles you'd expect from an episode of "Science Guy" yet no mention of it on any episode list, this is probably the closest thing to a "lost episode" as you're likely to see.
News articles:
https://archive.seattletimes.com/archive/?date=19970213&slug=2523796
https://www.deseret.com/1997/2/13/19294940/science-guy-aims-to-shield-kids-from-air-bag-hazards
