Thanks to Devilmanozzy for bringing us this, via Trendmaster collector Jonathan Shyman :http://ghostbusters.wikia.com/wiki/Extr ... on_Figures
Trendmasters did a prototype of the Garrett Miller figure. Garrett's wheelchair here is completely modified to have a massive ray gun or missile launcher instead of what is seen on Extreme Ghostbusters, and would not fit in the Ecto-1 Cruiser. His hair is also a lighter shade then his actual animated look, which was often the case with any prototype Trendmasters made before the final colors were established. This unique piece is most likely a one of a kind prototype, which was used as a Toy Fair Paint Master Sample, since it's completely done up, like most Toy Fair Samples."
There are some pictures at the link, and it looks like it would have been a pretty neat part of the line. The action figures and the cartoon didn't quite synch up (one of the main criticisms of the line) so giving Garrett a gaint battle chair wouldn't be too much out of place compared to the great big backpacks the others had.