Hey, when you will record your metro trip in the night, will be better t record the other side, to see the airport, the city lights and you what, you record the empty side, this is THE BADDEST video of recording sofia metro
Please, take video about Sofia metro announcement - Metro line M1 from Slivnica to Business Park and from Business Park to Slivnica and Metro line M2 from Sofia Airport to Vitosha and from Vitosha to Sofia Airport.