She was Bulgarian, the car the man was Bulgarian, you think the man was Bulgarian, so why did you start with " Strong Muslim Area"?
Thats the point. She was living alone in an area in which the residents are something like 95% Pakistani in origin. She was deliberately living there to service the "Muslim market" (for want of a better description). For another Bulgarian to be randomly parked up outside her house seemed more than a coincidence.
You'll often find in the northern mill towns that EE girls pick muslim/asian areas to live. Several reasons: the houses are cheap, the landlords don't ask questions, and they have a ready supply of muslim punters on the doorstep. Men who are barred from sex with women from their own community, so the girls are busy.
If the above sounds racist, its not meant to be. Its a simple explanation of how many EE girls think