Outside of large cities, Bulgaria often looks fairly bleak in Geoguessr. There is notably quite a lot of winter coverage, which contributes to the bleak feel. Bulgaria uses Cyrillic as the primary alphabet, but has a white Google car unlike Russia and Ukraine.
Plates
Standard EU plates. All taxis in Bulgaria have to be yellow by law
Road markings
The most noticeable thing is that roads in Bulgaria are often in very poor condition. You can often see potholes and unlevel ground - this seems to go hand-in-hand with where you also find winter coverage. However, larger roads are often in good condition, and have the same white lines as the rest of the east of europe.
Road signs
Signs for larger cities tend to be written on a blue background and villages on a white background
Poles
Poles in Bulgaria can have holes in them, or be made of concrete.
Scenery
Bulgaria is most known for its extensive winter coverage (although summer coverage exists as well). Dead trees and snow can be seen throughout the entire country. Bulgaria generally feels far less prosperous than the rest of Europe, and this is reflected in the roads and architecture.
Car metas
Bulgaria doesn't have any particular car meta. Sometimes there is a duct tape "flag" on the antenna which indicates Eastern Europe, however this can be found in several other countries as well.
Miscellaneous
Look out for the infamous Bulgarian dumpster - these are everywhere in Bulgaria, but be warned they sometimes wander into neighbouring countries.
