Episode: Brainiac
Poorly seen, a grey prison bus.
Alan Gryfe comments: "there have been junkyard scenes in several (c. half a dozen) episodes where numerous Can-Car Brill TC's (Canadian Car and Foundry T-48 trolley coaches, for the uninitiated) can be seen. These scenes were filmed in a lot in Surrey, British Columbia (see, there's a British connection!), not Seattle, Washington where the story is set." - one of these episodes is 'Borrowed Time'
Two of these trolleybuses were bought for use in the show: 2222 and 2316.
Carlos Wallberg reports a Silversides coach in another episode.
There is also an episode which features a GM New Look 4519.