Interesting, thanks for picking this up.
FYI this one is a bit of a funny car. The Starion was announced for group B in 83 and fell into development hell, never appearing in the category. Supposedly it was ready for certification in 86 but by that time several deaths caused the cancellation of the entire category, so it never went into production.
So the amount of cars built would be less than the fingers in one hand. That someone was able to sneak off with one of the prototypes and managed to get it fit for driving on public roads, it's quite a tall tale. Let's see how it develops.