I don't know if anyone knows but there is a second Easter egg song on transit it's a rock track, i think it could be called carry on. All i did was get the first bear at spawn then ride the bus all the way back to the bus stop then got the rest of the bears as normal expecting to hear the dubstep track but i got a rock track
Yes the track is by Avenged Sevenfold and it is called carry on.

Update: Got the Avenged Sevenfold track to play again i got the first bear at the bus stop next at the Bar then the farm...