I have noticed at Brands Hatch Indy there is one parking location where the Ai can't find its way out to pit lane from. It is the extra spots at the end of the paddock, specifically the one in the corner closest to what would be Surtees at the GP version. As you can see below this can have a drastic affect, especially in qualifying when several cars end up to damaged to set a time. This isn't an issue that affects the GP layout, just Indy. I have seen it happen with multiple cars not just those in these videos.
I can reproduce this issue in devmode. Problem seems to be only the garage spot 8/3. This car does not find his waypath to exit and rams some other cars which brings them also in trouble leaving the garages. Indy Layout: in comparison GP Layout here the car on 8/3 and all other leave without issues
... and maybe i found the problem. When marking the first waypoint of the pit extension as "cap end of path segment" all cars, also the 8/3, leave the garages without issues
I thought it was most likely an AIW issue with paths and waypoints, so I'm glad you confirmed it. Well done on finding the fix, hopefully it can be implemented in an update soon if someone from S397 see this thread.
Is this also why they drive the wrong way up pit lane, and try to take a hard right onto the track at the end of the pit wall? AI on this track - whatever layout - is badly broke.