There have been numerous questions about locations so I went ahead and completed a guide for each area with every item shown except for the ones that are required to beat the game (just a few character tokens and super builds). Be sure to check the descriptions for the times of all of the collectibles (use control+f to search the descriptions quickly). Here are the links:
Cherry Tree Hills https://www.youtube.com/watch?v=9NBbX3iEj2o
Albatross Island https://www.youtube.com/watch?v=m97Zscjp3WA
How can you get vehicles not from the vehicle tokens, and where? Are the bikes in this game?
I don't recall there being any bikes in this game unfortunately. As for vehicles without tokens, that is something I don't quite understand, but I know where they come from. Sometimes when you complete some of the characters special tasks, you will be rewarded with a vehicle or character token that you do not physically collect. It seems to be about 1 per character per area in the game, but it is not triggered upon the last item you find (i.e. aliens, generators, cats,etc), but rather one of them will give you the token.
On my game Downtown is the far right section at the Helipad and none show locked. I'm not sure why yours would show differently.
On another note, does the Civilian in the pause menu every stop showing the lock? I guess there are no side quests for civilian characters, but it looks odd to just leave a lock there when you scroll through the stats.